[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$f0nPyfhneB3vEkoSy9MA5RCC_PECGJreu9EBOLimxHeo":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":304,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":367},[4,8,12,16,20,24,28,32],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Authors","authors","\u002Fauthors\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"title":33,"slug":34,"path":35},"Tags","tags","\u002Ftags\u002F",{"type":37,"data":38},"blog",{"slug":39,"title":40,"description":41,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":44,"lastUpdatedDate":44,"draft":45,"category":46,"image":42,"body":47,"faq":48,"commentsClosed":45,"tags":49,"related":50,"comments":300},"nucleic-acid-amplification-tests-naat","Nucleic Acid Amplification Tests (NAAT): Principle, Types, and Interpretatio","\u003Cp>What NAATs are, the shared amplify-and-detect logic behind PCR, LAMP, and cartridge tests, how they compare with culture, and how to interpret a NAAT result.\u003C\u002Fp>",null,"Acharya Tankeshwar","2026-09-06",false,"molecular-biology","A patient with suspected tuberculous meningitis needs an answer today, not in six weeks. Culture is the reference standard, but it is far too slow to guide the first treatment decision, and the organism may be too scarce to see on a smear.\n\nA test that copies the pathogen's own genetic material until it can be detected gives the answer in hours. That family of tests is the nucleic acid amplification test, and it has reshaped how infections are diagnosed.\n\n## What a nucleic acid amplification test is\n\nA nucleic acid amplification test, or NAAT, is any laboratory method that detects an organism by making many copies of a specific piece of its genetic material (its DNA or RNA) until there is enough to detect. Instead of growing the organism, or waiting for the body to make antibodies against it, a NAAT goes straight to the pathogen's own nucleic acid and amplifies a chosen target sequence from a scarce, invisible amount to a readily detectable one.\n\nNAAT is an umbrella term, not a single test. Polymerase chain reaction is the best-known member, but the family also includes isothermal methods such as LAMP, cartridge-based systems such as the GeneXpert (CBNAAT), and TrueNat. What unites them is the core idea: find the target sequence, copy it many times, and detect the copies.\n\n## The shared logic: every NAAT does three things\n\nThe many NAAT methods look different on the bench, but they all carry out the same three tasks in sequence. Understanding these three steps once is the key to understanding the whole family, because each method is simply a different way of doing the middle step.\n\n**1. Extraction.** The nucleic acid is released and purified from the clinical sample (blood, sputum, cerebrospinal fluid, swab, tissue), separating it from everything else that could interfere with the reaction. Some cartridge-based systems automate this step inside a closed device.\n\n**2. Amplification.** A specific target sequence, chosen because it is unique to the organism, is copied many times over. This is the step that differs between methods. Polymerase chain reaction does it by cycling through temperatures; isothermal methods do it at a single constant temperature; each approach has its own enzymes and chemistry. The result is the same: a scarce target becomes abundant.\n\n**3. Detection.** The amplified product (the amplicon) is detected and, in quantitative methods, measured. Detection may use a fluorescent signal read in real time, a gel, a probe, or a line on a strip. Detecting the correct amplicon confirms that the target organism's sequence was present in the sample.\n\nEverything else in the NAAT family is a variation on how step 2 is performed and how step 3 is read. That is the single most useful idea on this page.\n\n## Why NAATs matter: what they do that culture and serology cannot\n\nBefore amplification methods, detecting a pathogen meant either growing it or detecting the immune response to it. Both have real limits that a NAAT bypasses.\n\nCulture is slow and fails for organisms that grow poorly or not at all. *Mycobacterium tuberculosis* takes weeks to grow; many viruses and some fastidious bacteria cannot be cultured routinely at all. Serology detects antibodies, which take time to appear and cannot separate current infection from past exposure.\n\nA NAAT detects the pathogen's nucleic acid directly, which gives it several advantages: speed (hours rather than days or weeks), sensitivity (it can detect very small numbers of organisms), specificity (the target sequence identifies the organism precisely), and reach (it works on organisms that cannot be cultured and on samples where culture would be uninterpretable). This is why NAATs have become central to diagnosing tuberculosis, HIV, hepatitis, SARS-CoV-2, and many other infections, and why the World Health Organization recommends rapid molecular tests as the initial diagnostic for tuberculosis.\n\n## The NAAT family\n\nThe methods below are grouped by how they amplify the target. Each is covered in full on its own page; this map shows how they relate.\n\n**Target amplification by temperature cycling: the PCR family.** Polymerase chain reaction copies the target by cycling through denaturation, annealing, and extension temperatures. Its variants adapt this for different needs:\n\n- Conventional PCR: the base method, detecting presence or absence. See the full guide on [polymerase chain reaction](https:\u002F\u002Fmicrobeonline.com\u002Fpolymerase-chain-reaction-pcr-steps-types-applications\u002F).\n- Real-time PCR (qPCR): amplifies and detects at the same time, and counts the copies, giving a quantitative result such as a viral load. See [real-time PCR](https:\u002F\u002Fmicrobeonline.com\u002Freal-time-pcr-principles-and-applications\u002F).\n- Reverse transcriptase PCR (RT-PCR): adds a step that converts RNA into DNA first, so RNA targets can be amplified. See [RT-PCR](https:\u002F\u002Fmicrobeonline.com\u002Frt-pcr-principles-applications\u002F).\n- Nested PCR: two successive rounds of primers for very high sensitivity in scarce samples. See [nested PCR](https:\u002F\u002Fmicrobeonline.com\u002Fnested-pcr-principle-applications\u002F).\n- Multiplex PCR: several targets amplified in one reaction, for panel testing. See [multiplex PCR](https:\u002F\u002Fmicrobeonline.com\u002Fmultiplex-pcr-principle-applications-and-limitations\u002F).\n\n**Amplification at a constant temperature: isothermal methods.** These avoid the need for a thermocycler, which suits point-of-care and lower-resource settings.\n\n- Loop-mediated isothermal amplification (LAMP) amplifies the target at one temperature with a set of specialized primers. See [LAMP](https:\u002F\u002Fmicrobeonline.com\u002Floop-mediated-isothermal-amplification-lamp\u002F).\n- TrueNat is a chip-based, battery-capable platform used for tuberculosis and other targets, designed for decentralized settings.\n\n**Cartridge-based, automated systems.** These enclose extraction, amplification, and detection in a single closed cartridge, so a NAAT can be run with minimal hands-on steps and little contamination risk.\n\n- GeneXpert (the platform behind CBNAAT) runs a self-contained real-time PCR and is widely used for tuberculosis and rifampicin resistance. See [GeneXpert MTB\u002FRIF](https:\u002F\u002Fmicrobeonline.com\u002Fgenexpert-mtbrif-assay-principle-procedure-results-interpretations\u002F).\n\n**Sequence-reading methods (related, not amplification alone).** These read the actual sequence and are used for identification, typing, and resistance prediction.\n\n- Sanger sequencing reads one sequence at a time. See [Sanger sequencing](https:\u002F\u002Fmicrobeonline.com\u002Fdna-sequencing-sanger-sequencing-method\u002F).\n- Next-generation sequencing reads vast numbers of sequences in parallel. See [next-generation sequencing](https:\u002F\u002Fmicrobeonline.com\u002Fnext-generation-sequencing\u002F).\n\n## Interpreting a NAAT result\n\nA NAAT result carries a specific meaning, and misreading it is a common and consequential error. These principles hold across every method in the family.\n\n**A NAAT detects nucleic acid, not necessarily a living organism.** Amplifiable DNA or RNA can persist after the organism is dead, for example after successful treatment. A positive NAAT confirms that the target sequence was present; it does not by itself prove viable, transmissible infection. This is why a NAAT can remain positive for a time after a patient has been treated, and why NAAT positivity is interpreted alongside the clinical picture.\n\n**A positive NAAT is only as specific as its target and its handling.** Because amplification is so powerful, even a trace of contaminating amplicon from a previous reaction can produce a false positive. This is the characteristic failure mode of NAATs and the reason for strict contamination control (discussed below). Conversely, a positive result for a well-designed target is highly specific for that organism.\n\n**A negative NAAT does not always exclude infection.** Sensitivity is high but not absolute. Inhibitors in the sample, a target present below the detection limit, sampling that missed the organism, or a sequence that differs from the primer can all give a false negative. A negative result is interpreted against how likely the infection was to begin with.\n\n**Quantitative results (viral load) mean more than presence.** Real-time methods report how much target is present, not just whether it is there. This copy number is used to monitor treatment (for example in HIV or hepatitis), where the trend over time matters more than any single value.\n\n**A NAAT for the organism is not a NAAT for its resistance.** Detecting a pathogen and detecting its drug-resistance gene are different questions. Some NAATs do both (for example, GeneXpert detects *M. tuberculosis* and rifampicin resistance together), but detecting the organism alone says nothing about susceptibility.\n\n## Quality control in the molecular laboratory\n\nBecause NAATs amplify so powerfully, their quality control is built around one dominant risk: contamination. A single stray amplicon carried over from a previous reaction can be amplified into a convincing false positive, so the molecular laboratory is organized to prevent carry-over above almost everything else.\n\n**Workflow separation.** The laboratory is physically divided into separate areas for reagent preparation, sample addition, amplification, and (where used) post-amplification product handling, with a one-directional workflow so that amplified product never moves back toward clean reagents. Dedicated equipment, coats, and often airflow are kept for each area.\n\n**Controls in every run.** A positive control confirms the reaction can amplify the target; a negative (no-template) control confirms no contamination is present; and an internal amplification control within the patient reaction confirms that a negative result is truly negative and not the result of inhibition. A run is interpreted only if its controls behave as expected, exactly as for any quality-controlled test.\n\n**Consumables and technique.** Filter (aerosol-barrier) pipette tips, careful tube handling, and closed-tube or cartridge-based methods all reduce the chance of carry-over. Closed systems such as real-time PCR and cartridge platforms are popular partly because they lower this contamination risk.\n\nThe principle to carry away: in the molecular laboratory, preventing contamination is not one quality-control task among many; it is the central one, because the power that makes NAATs sensitive is the same power that turns a trace contaminant into a false result.\n\n## How to remember\n\n- **NAAT = copy the pathogen's own code until you can see it.** Not grow it (culture), not detect the immune response to it (serology), but amplify its nucleic acid directly.\n- **Every NAAT does three things: extract, amplify, detect.** The methods differ only in how they amplify. PCR cycles temperatures; isothermal methods hold one temperature; cartridges do all three in a sealed box.\n- **The great strength is also the great weakness.** The power to copy a scarce target is the same power that copies a stray contaminant. That is why contamination control is the heart of molecular QC.\n- **Nucleic acid is not the same as a live organism.** A positive NAAT can persist after the organism is dead. Detection is not the same as viability.\n\n## Key Exam facts\n\n| Fact | Detail |\n| --- | --- |\n| What a NAAT is | A test that detects an organism by amplifying its DNA or RNA to a detectable level |\n| Umbrella covers | PCR and its variants, LAMP, TrueNat, GeneXpert\u002FCBNAAT, and related sequencing methods |\n| Three shared steps | Extraction, amplification, detection |\n| What differs between methods | The amplification step (temperature cycling vs. isothermal vs. cartridge) |\n| Advantages over culture | Speed (hours), sensitivity, specificity, works on non-cultivable organisms |\n| Characteristic failure mode | Contamination causing false positives |\n| Key interpretation caution | Detects nucleic acid, not necessarily viable organism |\n| Quantitative NAAT | Real-time PCR; reports copy number (e.g. viral load) for monitoring |\n| Core of molecular QC | Contamination control: workflow separation, controls in every run, filter tips |\n| WHO position (TB) | Rapid molecular tests recommended as the initial diagnostic for tuberculosis |\n\n## Where students get confused\n\n**\"NAAT and PCR are the same thing.\"** PCR is one NAAT, the most common one, but NAAT is the whole family. LAMP, GeneXpert\u002FCBNAAT, and TrueNat are NAATs that are not conventional PCR. Saying \"NAAT\" is like saying \"antibiotic\"; PCR is one member.\n\n**\"A positive NAAT means a live, active infection.\"** It means the target nucleic acid was present. Nucleic acid can persist after the organism is dead, so a NAAT can stay positive after treatment. Positivity is read together with the clinical picture, not alone.\n\n**\"A negative NAAT rules out the infection.\"** It makes it less likely but does not exclude it. Inhibitors, a target below the detection limit, or sampling that missed the organism can all cause a false negative. The internal control helps show whether a negative is trustworthy.\n\n**\"A NAAT that finds the organism also tells you the resistance.\"** Only if it specifically targets a resistance gene. Detecting a pathogen and detecting its resistance are separate questions; some tests do both, most do not.\n\n**\"Contamination control is just general lab tidiness.\"** In the molecular laboratory it is the central quality issue, because amplification turns a trace of carried-over product into a false positive. This is why the workflow is physically separated and directional.\n\n## References\n\n1. Tille PM. *Bailey & Scott's Diagnostic Microbiology.* 15th ed. St. Louis: Elsevier; 2022.\n2. Procop GW, et al. *Koneman's Color Atlas and Textbook of Diagnostic Microbiology.* 7th ed. Philadelphia: Wolters Kluwer; 2017.\n3. Leber AL, editor. *Clinical Microbiology Procedures Handbook.* 4th ed. Washington, DC: ASM Press; 2016. doi:10.1128\u002F9781683670438.CMPH\n4. World Health Organization. *WHO consolidated guidelines on tuberculosis. Module 3: Diagnosis.* 4th ed. Geneva: World Health Organization; 2025.",[],[],[51,80,103,125,147,176,216,262],{"slug":52,"title":53,"description":54,"seoTitle":55,"seoDescription":56,"author":43,"createdDate":57,"lastUpdatedDate":44,"draft":45,"category":58,"image":42,"faq":59,"tags":78},"polymerase-chain-reaction-pcr-steps-types-applications","Polymerase Chain Reaction (PCR): Steps, Types, and Applications","PCR amplifies DNA exponentially in three steps: denaturation, annealing, and extension. Learn the components, steps, types: nested, multiplex, real-time, RT-PCR and clinical applications in diagnostic microbiology.","PCR: Steps, Reagents, Result Interpretation, and Applications","Review PCR reagents and the denaturation, annealing, and extension cycle, then compare major PCR variants, controls, interpretation, and applications.","2016-07-07","lab-equipment",[60,63,66,69,72,75],{"question":61,"answer":62},"What is polymerase chain reaction (PCR) and what does it do?","\u003Cp>Polymerase chain reaction (PCR) is an in vitro molecular technique that amplifies a specific DNA or RNA sequence exponentially, producing up to 10 million copies from a single starting template within a few hours. It works by repeatedly cycling through three temperature-controlled steps (denaturation, annealing, and extension), using a heat-stable DNA polymerase (Taq polymerase) and short synthetic primers that define the target sequence. In clinical microbiology, PCR directly detects a pathogen's nucleic acid in a patient specimen, regardless of whether the organism is alive, cultivable, or present in small quantities.\u003C\u002Fp>",{"question":64,"answer":65},"What are the three steps of PCR and what temperature is used for each?","\u003Cp>PCR has three steps that repeat in each cycle. Denaturation occurs at 94–96°C, heat breaks the hydrogen bonds between the two DNA strands, separating them into single-stranded templates. Annealing occurs at 45–65°C, the temperature is lowered so primers can bind to their complementary sequences on each strand. Extension occurs at 72°C, Taq polymerase synthesizes a new complementary DNA strand starting from each primer. After 30–40 cycles, the target sequence is amplified by a factor of approximately 10 million.\u003C\u002Fp>",{"question":67,"answer":68},"What is Taq polymerase and why is it used in PCR?","\u003Cp>Taq polymerase is a thermostable DNA polymerase originally isolated from Thermus aquaticus, a bacterium that lives in boiling hot springs. Its defining property is heat stability, it remains active at 72°C and survives the 94°C denaturation step without being destroyed. This allows automated PCR cycling without adding fresh enzyme after every cycle. Without a heat-stable polymerase, PCR as an automated process would not be possible.\u003C\u002Fp>",{"question":70,"answer":71},"What is the difference between RT-PCR and real-time PCR?","\u003Cp>These two terms describe different aspects of PCR and are frequently confused. RT-PCR (reverse transcriptase PCR) refers to the template type: it adds a reverse transcription step that converts RNA into complementary DNA before amplification, making it possible to detect RNA viruses such as HIV, hepatitis C, dengue, and SARS-CoV-2. Real-time PCR (quantitative PCR or qPCR) refers to the detection method: fluorescence is measured during each amplification cycle, allowing quantitation of the target. A test can be both simultaneously: the COVID-19 PCR test is technically RT-qPCR, using reverse transcriptase for the RNA template and real-time detection for quantitation.\u003C\u002Fp>",{"question":73,"answer":74},"When should nested PCR be used instead of standard PCR?","\u003Cp>Nested PCR should be used when the target organism is present in very low quantities, below the detection threshold of standard single-round PCR. It uses two successive PCR reactions with two primer sets: outer primers amplify a large fragment first, then inner (nested) primers amplify a smaller specific region within that product. The double amplification dramatically increases sensitivity. Clinical applications include detection of \u003Cem>Rickettsia\u003C\u002Fem> and \u003Cem>Bartonella\u003C\u002Fem> in blood, \u003Cem>M. tuberculosis\u003C\u002Fem> in paucibacillary samples, herpesviruses and enteroviruses in CSF, and \u003Cem>Leishmania\u003C\u002Fem> in tissue.\u003C\u002Fp>",{"question":76,"answer":77},"What are the advantages of PCR over culture in clinical microbiology?","\u003Cp>PCR offers four key advantages over culture. Speed: results in hours rather than days: TB culture takes 6–8 weeks; PCR confirms TB the same day. Sensitivity: detects as few as 1–10 DNA copies per reaction, far below the threshold for culture positivity. Specificity: primers target a defined sequence, identifying the exact organism or resistance gene rather than just confirming growth. Versatility: works on organisms that cannot be cultured (many viruses, some parasites), on degraded specimens (formalin-fixed tissue, dried blood), and on samples with mixed flora where culture is uninterpretable.\u003C\u002Fp>",[79],"pcr-techniques",{"slug":81,"title":82,"description":83,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":84,"lastUpdatedDate":85,"draft":45,"category":58,"image":42,"faq":86,"tags":102},"real-time-pcr-principles-and-applications","Real-time PCR (qPCR): Principles and Applications","Real-time PCR (qPCR) amplifies and quantifies DNA simultaneously using fluorescent probes. Learn SYBR Green vs TaqMan, Ct values, and clinical uses in viral load testing.","2019-12-26","2026-07-05",[87,90,93,96,99],{"question":88,"answer":89},"What is the Ct value in real-time PCR and how is it interpreted?","The Ct value (cycle threshold) is the PCR cycle number at which the fluorescent signal from the reaction crosses a pre-set detection threshold. It is inversely proportional to the amount of starting template: a sample with high viral load reaches the threshold in fewer cycles (low Ct value), while a sample with low viral load requires more cycles (high Ct value). In HIV viral load monitoring, a Ct of approximately 20 corresponds to a high viral load, while a Ct above 34 indicates very low or undetectable levels. An important caveat: Ct values are not directly comparable between different assays, instruments, or laboratories.",{"question":91,"answer":92},"What is the difference between SYBR Green and TaqMan probes in real-time PCR?","SYBR Green is a fluorescent dye that binds to any double-stranded DNA and fluoresces — it is non-specific, detecting all amplification products including primer dimers and non-specific products. It is cheaper and simpler but requires melting curve analysis to confirm the correct product was amplified. TaqMan probes are sequence-specific — a labelled probe complementary to an internal target sequence is cleaved by Taq polymerase during extension, releasing a fluorescent reporter only when the correct sequence is amplified. TaqMan is more specific, suitable for multiplex detection, and is the standard for clinical diagnostic assays. SYBR Green is used in research settings where cost matters and melting curve verification is feasible.",{"question":94,"answer":95},"How does real-time PCR differ from conventional PCR?","In conventional PCR, amplification and detection are separate steps — the tube is opened after cycling and products are detected by gel electrophoresis. In real-time PCR, amplification and detection occur simultaneously in a closed tube — fluorescence is measured after each cycle as amplicon accumulates. The closed-tube design eliminates post-PCR handling and the carry-over contamination risk it creates. Real-time PCR is also quantitative, measuring the amount of starting template, while conventional PCR is qualitative (presence or absence only). Real-time PCR is faster because no gel electrophoresis step is required.",{"question":97,"answer":98},"What are the clinical applications of real-time PCR in microbiology?","Real-time PCR is used for viral load quantification — HIV, HCV, HBV, and CMV monitoring in transplant patients all rely on qPCR to measure virus copy numbers and guide treatment decisions. It is used for COVID-19 (SARS-CoV-2) detection, TB quantification, and diagnosis of infections where pathogen load correlates with disease severity or treatment response. It is also used for SNP detection, allelic discrimination, and — when combined with reverse transcription — for mRNA expression analysis and RNA virus detection.",{"question":100,"answer":101},"Why is real-time PCR preferred over conventional PCR in clinical diagnostic laboratories?","Real-time PCR is preferred for three reasons. First, the closed-tube format eliminates post-PCR amplicon manipulation, dramatically reducing the risk of carry-over contamination that causes false positives — a major problem in high-throughput diagnostic laboratories. Second, it is quantitative, providing viral load or copy number data that guides clinical decisions such as when to start or switch antiviral therapy. Third, it is faster — results are available in 1–3 hours compared to 4–6 hours for conventional PCR followed by gel electrophoresis.",[79],{"slug":104,"title":105,"description":106,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":107,"lastUpdatedDate":85,"draft":45,"category":58,"image":42,"faq":108,"tags":124},"rt-pcr-principles-applications","Reverse transcriptase (RT)-PCR: Principles, Applications","RT-PCR converts RNA to cDNA using reverse transcriptase before PCR amplification. Learn one-step vs two-step methods, primer types, and clinical uses in RNA virus detection.","2019-12-16",[109,112,115,118,121],{"question":110,"answer":111},"What does reverse transcriptase PCR (RT-PCR) detect that standard PCR cannot?","RT-PCR detects RNA targets — standard PCR cannot, because it requires a DNA template. RT-PCR adds a reverse transcription step before amplification: the enzyme reverse transcriptase converts single-stranded RNA into complementary DNA (cDNA), which is then amplified by standard PCR. This makes RT-PCR essential for detecting RNA viruses — HIV, hepatitis C, dengue, influenza, SARS-CoV-2, enteroviruses, and West Nile virus all have RNA genomes. RT-PCR can also detect bacterial and parasitic rRNA, and is used to study mRNA gene expression.",{"question":113,"answer":114},"What is the difference between one-step and two-step RT-PCR?","In one-step RT-PCR, reverse transcription and PCR amplification occur in the same tube using a single reaction buffer and gene-specific primers. This minimises sample handling, reduces contamination risk, and is faster — making it the preferred format for clinical diagnostics where a single RNA target needs detection. In two-step RT-PCR, reverse transcription is performed in a first reaction to generate cDNA, which is then stored and used as template for subsequent PCR reactions. This is slower and requires more handling, but the cDNA can be used to amplify multiple different gene targets — making it the preferred format for research and gene expression studies.",{"question":116,"answer":117},"What types of primers are used for cDNA synthesis in RT-PCR?","Three primer types are used for the reverse transcription step. Random hexamers are mixtures of all possible six-nucleotide combinations that bind randomly to any RNA and generate cDNA from the entire RNA pool. Oligo-dT primers are complementary to the poly-A tail present on mRNA molecules, producing cDNA from mRNA only. Gene-specific primers bind selectively to the mRNA of interest, making reverse transcription a targeted process. Random hexamers give the broadest coverage; oligo-dT targets mRNA specifically; gene-specific primers are the most restricted and most targeted.",{"question":119,"answer":120},"Why does RT-PCR detect viable organisms better than standard DNA PCR?","DNA is chemically stable and persists in dead cells for extended periods after an organism has been killed — meaning standard PCR can return a positive result from non-viable organisms weeks after successful treatment. RNA, by contrast, degrades rapidly after cell death because RNA molecules are intrinsically unstable and are immediately targeted by cellular RNases when the organism dies. Detecting rRNA by RT-PCR therefore indicates the presence of metabolically active, viable organisms. This makes RT-PCR targeting rRNA more informative than DNA PCR when assessing treatment response or distinguishing active infection from residual nucleic acid.",{"question":122,"answer":123},"What is RT-qPCR and how does it differ from RT-PCR?","RT-qPCR (reverse transcriptase quantitative PCR) combines two methods: the reverse transcription step of RT-PCR (converting RNA to cDNA) with the real-time fluorescent detection of qPCR (measuring amplification during each cycle). RT-PCR alone detects presence or absence of an RNA target qualitatively. RT-qPCR quantifies how much RNA is present — expressed as copy number or viral load. HIV viral load and HCV viral load assays are RT-qPCR: they use reverse transcriptase because the targets are RNA viruses, and real-time detection to quantify the viral load for treatment monitoring.",[79],{"slug":126,"title":127,"description":128,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":129,"lastUpdatedDate":85,"draft":45,"category":58,"image":42,"faq":130,"tags":146},"nested-pcr-principle-applications","Nested PCR: Principle and Applications","Nested PCR uses two successive PCR reactions with outer and inner primer sets to maximise sensitivity and specificity. Learn its principle, applications, and contamination risk.","2019-12-20",[131,134,137,140,143],{"question":132,"answer":133},"What is nested PCR and how does it increase sensitivity?","Nested PCR uses two successive PCR reactions targeting the same region. The first reaction uses outer primers to amplify a large fragment of the target sequence. The product of that first reaction becomes the template for the second reaction, which uses inner (nested) primers to amplify a smaller region within the first amplicon. This double amplification increases sensitivity dramatically — a target present in too few copies to be reliably detected in a single PCR round is enriched by the first reaction, making it readily detectable in the second. Nested PCR is the most sensitive PCR method for detecting organisms present in very low quantities.",{"question":135,"answer":136},"Why does nested PCR also increase specificity?","Nested PCR increases specificity because the inner primers only find binding sites within the specific first-round product. Non-specific products generated in the first round — amplicons from non-target sequences that share partial homology with the outer primers — are unlikely to contain binding sites for the inner primers. The second round of amplification therefore selectively amplifies the genuine target while eliminating most non-specific products from the first round. Two independent primer-binding events on the same target provide a level of confirmation that a single primer set cannot offer.",{"question":138,"answer":139},"What is single-tube nested PCR (STNPCR) and why was it developed?","Traditional nested PCR requires opening the first-round reaction tube to transfer product to a second tube for the second PCR reaction. This step releases amplicons into the laboratory environment, where they can contaminate subsequent runs and cause false positives — a serious problem given nested PCR's extreme sensitivity. Single-tube nested PCR (STNPCR) was developed to eliminate this risk: both sets of primers are added to the initial reaction vessel before cycling begins, and an extended PCR protocol activates the inner primers at the appropriate stage without ever opening the tube. STNPCR maintains the sensitivity advantages of nested PCR while reducing contamination risk.",{"question":141,"answer":142},"What clinical infections is nested PCR particularly useful for?","Nested PCR is particularly useful for infections where the pathogen circulates in blood or tissues at very low copy numbers, making standard PCR unreliable. Established applications include: detection of Rickettsia and Bartonella in blood during bacteraemia; detection of M. tuberculosis in paucibacillary samples (e.g., CSF in TB meningitis, pleural fluid); detection of herpesvirus and enterovirus in CSF; detection of Leishmania in tissue biopsies; and detection of organisms in formalin-fixed paraffin-embedded tissue where nucleic acid degradation limits PCR sensitivity. The BioFire FilmArray commercial system uses nested PCR as its first amplification stage.",{"question":144,"answer":145},"What are the main limitations of nested PCR?","The two main limitations are contamination risk and cost. Contamination risk is the most serious: the extreme sensitivity that makes nested PCR valuable also makes it exquisitely susceptible to carry-over contamination. First-round amplicons opening into the laboratory environment can contaminate reagents, surfaces, and subsequent reactions, producing false positives that are difficult to identify and eliminate. STNPCR mitigates but does not entirely eliminate this risk. Cost is the second limitation: two separate PCR reactions are required to produce one result, and if contamination causes a repeat, cost escalates further. Nested PCR is therefore reserved for situations where standard PCR lacks sufficient sensitivity rather than used as a first-line method.",[79],{"slug":148,"title":149,"description":150,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":151,"lastUpdatedDate":152,"draft":45,"category":58,"image":42,"faq":153,"tags":175},"multiplex-pcr-principle-applications-and-limitations","Multiplex PCR: Principle, Procedure, Advantages, and Limitations","Multiplex PCR amplifies multiple targets simultaneously in one reaction. Learn primer design considerations, advantages, clinical applications, and limitations in diagnostic microbiology.","2019-12-18","2026-08-23",[154,157,160,163,166,169,172],{"question":155,"answer":156},"What is multiplex PCR and how does it differ from standard PCR?","\u003Cp>Multiplex PCR includes multiple primer pairs in a single PCR reaction, enabling simultaneous amplification of several different target sequences at once. Standard PCR uses one primer pair to detect one target per reaction. Multiplex PCR detects multiple targets (from different organisms or different genes) in the same tube, saving sample volume, reagent cost, and time. \u003C\u002Fp>\u003Cp>\u003C\u002Fp>\u003Cp>Each primer pair produces an amplicon of a specific size, allowing identification of each target by band size on gel or by probe-specific fluorescence in real-time multiplex assays.\u003C\u002Fp>",{"question":158,"answer":159},"What is the role of the internal amplification control in multiplex PCR?","\u003Cp>The internal amplification control is a primer pair directed at a sequence present in all specimens such as a universal bacterial gene or a human housekeeping gene, included in every multiplex PCR reaction. It serves as a quality gate: if the control amplicon is detected, the PCR conditions were met and a negative result for the test targets can be confidently interpreted as true negative. \u003C\u002Fp>\u003Cp>\u003C\u002Fp>\u003Cp>If the control amplicon is absent, the PCR failed, likely due to inhibitors, degraded nucleic acid, or technical error and the negative result is uninterpretable. The internal control is what distinguishes a reliable negative from a failed reaction.\u003C\u002Fp>",{"question":161,"answer":162},"What are the main clinical applications of multiplex PCR in microbiology?","\u003Cp>Multiplex PCR is used whenever a clinical syndrome can be caused by multiple pathogens and rapid identification is needed from a limited sample volume. Key applications include: bacterial meningitis panels detecting \u003Cem>S. pneumoniae, H. influenzae\u003C\u002Fem>, and \u003Cem>N. meningitidis \u003C\u002Fem>simultaneously from CSF; respiratory virus panels detecting influenza A, influenza B, RSV, and other respiratory pathogens from nasopharyngeal swabs; gastrointestinal pathogen panels; and sexually transmitted infection panels. \u003C\u002Fp>\u003Cp>\u003C\u002Fp>\u003Cp>The BioFire FilmArray system (which combines nested, multiplex, and singleplex PCR in an automated closed pouch) is the most widely deployed commercial application.\u003C\u002Fp>",{"question":164,"answer":165},"Why is multiplex PCR challenging to optimise?","\u003Cp>Optimizing multiplex PCR is challenging because each primer pair has different ideal conditions: melting temperature, MgCl₂ requirement, and amplification efficiency. When multiple primer pairs are combined, more efficient pairs can out-compete less efficient ones, producing strong bands for some targets and weak or absent bands for others (competitive amplification). \u003C\u002Fp>\u003Cp>\u003C\u002Fp>\u003Cp>Primers from different pairs can also interact with each other, forming cross-dimers that consume reagents. Finding annealing temperature and buffer conditions that satisfy all primer pairs simultaneously requires systematic optimization (adjusting primer concentrations, MgCl₂, and cycling parameters) which becomes increasingly complex as the number of targets increases.\u003C\u002Fp>",{"question":167,"answer":168},"\u003Cp>How is multiplex PCR different from real-time (quantitative) PCR?\u003C\u002Fp>","\u003Cp>They describe different things. Multiplex means many targets are tested in one reaction. Real-time PCR means the product is measured as it forms, often to find out how much is present. A test can be multiplex, real-time, or both at once, so the two terms are not synonyms.\u003C\u002Fp>",{"question":170,"answer":171},"\u003Cp>What are the advantages and disadvantages of multiplex PCR?\u003C\u002Fp>","\u003Cp>The main advantages are that it detects several targets from one small sample, saving specimen volume, time, and cost, and that a built-in internal control can confirm the reaction worked so a negative result can be trusted. The main disadvantages come from combining several primer pairs in one reaction: the primers can interfere with each other, some targets can out-compete others, and the reaction takes careful optimization to balance. It works best for a limited, defined set of targets.\u003C\u002Fp>",{"question":173,"answer":174},"\u003Cp>What is the principle of multiplex PCR?\u003C\u002Fp>","\u003Cp>The principle is the same as standard PCR, with one difference: several primer pairs are added to the same reaction, and each pair binds and copies only its own target. Because all the pairs share one tube and one temperature program, they must be designed to work under the same conditions. The different products are then told apart either by their size or by a colored probe for each target.\u003C\u002Fp>",[79],{"slug":177,"title":178,"description":179,"seoTitle":42,"seoDescription":42,"author":180,"createdDate":181,"lastUpdatedDate":182,"draft":45,"category":46,"image":42,"faq":183,"tags":214},"loop-mediated-isothermal-amplification-lamp","Loop-Mediated Isothermal Amplification (LAMP): Principle, Mechanism, and Applications","\u003Cp>LAMP amplifies DNA at one constant temperature using six primers and Bst polymerase, with no thermocycler. Learn the principle, the step-by-step mechanism, detection methods, and how LAMP compares with PCR.\u003C\u002Fp>","Srijana Khanal","2022-06-04","2026-08-16",[184,187,190,193,196,199,202,205,208,211],{"question":185,"answer":186},"\u003Cp>What is the full form of LAMP in microbiology?\u003C\u002Fp>","\u003Cp>LAMP stands for Loop-Mediated Isothermal Amplification. It is a method that copies a specific DNA sequence millions of times at a single constant temperature, without the repeated heating and cooling that PCR requires.\u003C\u002Fp>",{"question":188,"answer":189},"\u003Cp>What is the principle of LAMP?\u003C\u002Fp>","\u003Cp>LAMP relies on two things. First, it uses \u003Cem>Bst\u003C\u002Fem> DNA polymerase, an enzyme with strong strand displacement activity, so it can separate DNA strands as it copies them and never needs a high-temperature step. Second, it uses inner primers built from two joined segments, which make the newly made DNA fold back on itself into loops. These loops let the reaction restart on its own again and again at one temperature, so copies build up very quickly.\u003C\u002Fp>",{"question":191,"answer":192},"\u003Cp>What temperature does LAMP run at?\u003C\u002Fp>","\u003Cp>LAMP runs at a single constant temperature, usually 60 to 65 °C. This is why it is called isothermal and why it does not need a thermocycler. A simple water bath or heat block is enough.\u003C\u002Fp>",{"question":194,"answer":195},"\u003Cp>How is LAMP different from PCR?\u003C\u002Fp>","\u003Cp>PCR cycles between different temperatures to separate DNA strands by heat, so it needs a thermocycler and takes longer. LAMP works at one temperature because the enzyme itself displaces the strands, so it needs only a simple heat source and gives results in 15 to 60 minutes. LAMP also uses six or more primers against six to eight regions, compared with two primers in PCR, which makes it very specific. PCR is still preferred where accurate quantification or multiplexing is needed.\u003C\u002Fp>",{"question":197,"answer":198},"\u003Cp>Which enzyme is used in LAMP?\u003C\u002Fp>","\u003Cp>\u003Cem>Bst\u003C\u002Fem> DNA polymerase, originally from the bacterium \u003Cem>Bacillus stearothermophilus\u003C\u002Fem>. Its key feature is strong strand displacement activity, which lets it push aside the old DNA strand as it synthesizes a new one. This is what removes the need for a heat denaturation step and allows the whole reaction to run at one temperature.\u003C\u002Fp>",{"question":200,"answer":201},"\u003Cp>How many primers does LAMP use and why so many?\u003C\u002Fp>","\u003Cp>LAMP uses four core primers (two outer, F3 and B3, and two inner, FIP and BIP) that recognize six regions of the target. Two optional loop primers can be added to speed the reaction. The inner primers are special because each is made of two joined sequences, and this design is what makes the DNA fold into loops. Using so many regions also makes LAMP highly specific, because amplification only proceeds when all the regions are correctly matched.\u003C\u002Fp>",{"question":203,"answer":204},"\u003Cp>Why does LAMP form loop structures?\u003C\u002Fp>","\u003Cp>Because of the inner primers. FIP carries an F2 segment and an F1c segment joined together, so the strand it helps build contains two complementary regions (F1 and F1c) on the same strand. Complementary regions on one strand pair with each other, so the strand folds back into a loop. The same happens at the other end with BIP, producing a dumbbell-shaped molecule with a loop at each end. These loops are what allow the reaction to keep cycling on its own.\u003C\u002Fp>",{"question":206,"answer":207},"\u003Cp>What is RT-LAMP?\u003C\u002Fp>","\u003Cp>RT-LAMP is LAMP used to detect RNA rather than DNA. A reverse transcriptase enzyme first copies the RNA target into DNA, and then the normal LAMP reaction amplifies it. RT-LAMP was widely used to detect the RNA virus SARS-CoV-2 during the COVID-19 pandemic, often with a simple color change read by eye.\u003C\u002Fp>",{"question":209,"answer":210},"\u003Cp>How are LAMP results detected?\u003C\u002Fp>","\u003Cp>LAMP results can be read in several ways. Turbidity: amplification produces magnesium pyrophosphate, which makes the solution cloudy. Color: a pH indicator such as phenol red changes color as the reaction lowers the pH, turning a positive sample from pink to yellow. Fluorescence: dyes or probes give a signal that can be measured in real time. The color and turbidity readouts can often be seen with the naked eye, which is a major advantage in field settings.\u003C\u002Fp>",{"question":212,"answer":213},"\u003Cp>What are the limitations of LAMP?\u003C\u002Fp>","\u003Cp>Designing the primers is complex, because several primers must be optimized together. The high sensitivity means contamination can cause false positives, so careful handling is essential. LAMP is also harder to quantify than real-time PCR and is difficult to multiplex, meaning it is not easy to test for several targets in one reaction.\u003C\u002Fp>",[215],"molecular-technique",{"slug":217,"title":218,"description":219,"seoTitle":220,"seoDescription":42,"author":43,"createdDate":221,"lastUpdatedDate":44,"draft":45,"category":222,"image":42,"faq":223,"tags":260},"genexpert-mtbrif-assay-principle-procedure-results-interpretations","GeneXpert MTB\u002FRIF: How to Read the Result and What to Do Next","Semi-quantitative grades, probe-level RIF calls, error codes, and the traps: why a \"RIF resistance detected\" result still needs confirmation and why \"not detected\" never rules out TB.","GeneXpert MTB\u002FRIF Assay: Principle, Procedure, Results, and Interpretation","2016-01-04","bacteriology",[224,227,230,233,236,239,242,245,248,251,254,257],{"question":225,"answer":226},"Does GeneXpert detect isoniazid resistance?","No. The assay reads only the rpoB gene and reports rifampicin resistance. Isoniazid resistance requires a line probe assay, targeted sequencing, or phenotypic DST. Because rifampicin resistance usually co-exists with isoniazid resistance, a positive RIF result is used as a marker for probable MDR-TB, but it is an inference, not a measurement.",{"question":228,"answer":229},"Can GeneXpert replace sputum smear microscopy and culture?","It replaces smear microscopy as the initial diagnostic test under current WHO guidance. It does not replace culture. Culture is still needed for phenotypic drug susceptibility testing, genotyping, detection of non-tuberculous mycobacteria, and confirmation of cure.",{"question":231,"answer":232},"What does \"MTB detected, trace\" mean?","It means the multicopy IS6110 or IS1081 targets were detected but rpoB was essentially unread, so bacillary load is at the very bottom of the assay's range and rifampicin resistance cannot be reported. In children, people living with HIV, and extrapulmonary specimens, trace counts as bacteriological confirmation of TB. In previously treated adults it should be repeated on a fresh specimen, because it may represent residual DNA from cured disease.",{"question":234,"answer":235},"Why does the report say \"very low\" or \"high\"?","That is the semi-quantitative grade, derived from the cycle threshold of the first rpoB probe to bind. It estimates bacillary load, which relates to infectiousness, to how reliable the rifampicin call is, and to the likelihood that a weak positive represents old rather than active disease.",{"question":237,"answer":238},"What is the difference between Invalid and Error?","Invalid means the Sample Processing Control failed: something about the specimen, usually inhibitors or inadequate processing, prevented a trustworthy result. Repeat with a new specimen. Error means the run aborted on an instrument or cartridge fault, most often a failed probe check or a pressure problem. Repeat with a new cartridge.",{"question":240,"answer":241},"Can a GeneXpert result be falsely positive for rifampicin resistance?","Yes. The assay infers resistance from a probe failing to bind, not from reading the mutation, so silent mutations and non-resistance-conferring polymorphisms in the RRDR are reported as resistance. False positives are most common on paucibacillary specimens. This is why a positive result should be confirmed by a line probe assay, targeted sequencing, or phenotypic DST, while treatment is started in parallel.",{"question":243,"answer":244},"Can GeneXpert miss rifampicin resistance?","Yes. Approximately 5% of rifampicin-resistant strains carry mutations outside the 81-bp RRDR. These leave all probes binding normally and are reported as susceptible.",{"question":246,"answer":247},"How long does the GeneXpert MTB\u002FRIF test take?","Under two hours from loading. The standard Xpert MTB\u002FRIF run is about 112 minutes; Xpert Ultra is faster at roughly 65 to 87 minutes. Specimen preparation adds about 15 to 20 minutes before loading.",{"question":249,"answer":250},"Can GeneXpert be used on non-sputum specimens?","Yes. WHO endorses its use on CSF, lymph node aspirate and tissue, gastric aspirate, nasopharyngeal aspirate, and stool, with sensitivity varying by specimen type. It is strongly recommended as the initial test in suspected TB meningitis. Sensitivity is lowest in pleural fluid.",{"question":252,"answer":253},"Can GeneXpert be used to monitor response to treatment?","No. It detects DNA from both living and dead bacilli, so it can remain positive for months in patients who are responding well. Smear microscopy and culture are used for treatment monitoring.",{"question":255,"answer":256},"Does a positive GeneXpert distinguish M. tuberculosis from M. bovis?","No. It detects the M. tuberculosis complex as a group and cannot separate M. tuberculosis, M. bovis, M. africanum, or BCG. Species-level identification requires culture-based methods.",{"question":258,"answer":259},"Is a biological safety cabinet required to run GeneXpert?","Specimen manipulation before the 15-minute inactivation step should be done in a Class II BSC where available. After that step the cartridge is closed and the risk is minimal. WHO permits Xpert testing at the same biosafety level as direct sputum smear microscopy in settings without a BSC.",[261],"mycobacteria",{"slug":263,"title":264,"description":265,"seoTitle":42,"seoDescription":42,"author":266,"createdDate":267,"lastUpdatedDate":182,"draft":45,"category":46,"image":42,"faq":268,"tags":299},"dna-sequencing-sanger-sequencing-method","Sanger Sequencing (Dideoxy Chain-Termination Method): Principle, Steps, and Uses","\u003Cp>Sanger sequencing reads a DNA sequence using dideoxynucleotides (ddNTPs) that stop the chain wherever they are added. Learn the principle, the step-by-step method, how to read the result, and why it is still the gold standard.\u003C\u002Fp>","Aastha Shrestha","2022-11-26",[269,272,275,278,281,284,287,290,293,296],{"question":270,"answer":271},"\u003Cp>What is Sanger sequencing?\u003C\u002Fp>","\u003Cp>Sanger sequencing is a method for reading the exact order of bases in a piece of DNA. It was developed by Frederick Sanger in 1977 and is also called the dideoxy method or the chain-termination method. It works by using special bases that stop a growing DNA strand at known points, so the sequence can be read from the lengths of the fragments produced.\u003C\u002Fp>",{"question":273,"answer":274},"\u003Cp>What is the principle of Sanger sequencing?\u003C\u002Fp>","\u003Cp>The principle is chain termination. DNA polymerase builds a new strand using normal nucleotides, but the reaction also contains a small amount of dideoxynucleotides (ddNTPs), which lack the 3′-OH group needed to add the next base. Whenever a ddNTP is added, that strand stops. Because this happens at random positions, the reaction produces fragments of every possible length, each ending in a known base. Sorting the fragments by length and reading the terminating base of each in order gives the sequence.\u003C\u002Fp>",{"question":276,"answer":277},"\u003Cp>What is the difference between a dNTP and a ddNTP?\u003C\u002Fp>","\u003Cp>A dNTP is a normal nucleotide and has a 3′-OH group, so the DNA chain can keep growing after it is added. A ddNTP is a modified nucleotide that lacks the 3′-OH group (it has a hydrogen there instead), so once it is added no further base can attach and the chain stops. This single difference is the entire basis of Sanger sequencing.\u003C\u002Fp>",{"question":279,"answer":280},"\u003Cp>Why does the DNA chain stop when a ddNTP is added?\u003C\u002Fp>","\u003Cp>DNA polymerase adds each new base by attaching it to the 3′-OH group of the previous nucleotide. A ddNTP has no 3′-OH group, so there is nothing for the next base to attach to. The strand cannot grow any further and terminates at that point.\u003C\u002Fp>",{"question":282,"answer":283},"\u003Cp>What are the steps of Sanger sequencing?\u003C\u002Fp>","\u003Cp>The main steps are: separate the DNA into single strands (denaturation), bind a primer to give a starting point, extend the new strand with DNA polymerase while ddNTPs randomly terminate it at different lengths, separate the resulting fragments by size using capillary electrophoresis, and read the fluorescent color of each fragment's terminating base to build the sequence as a chromatogram.\u003C\u002Fp>",{"question":285,"answer":286},"\u003Cp>How is the sequence actually read from the fragments?\u003C\u002Fp>","\u003Cp>The fragments are sorted by length. The shortest fragment stopped earliest, so its terminating base is the first base in the sequence. The next-longest gives the second base, and so on. In modern machines each of the four bases carries a different fluorescent color, so a laser reads the color of each fragment as it passes and records the bases in order.\u003C\u002Fp>",{"question":288,"answer":289},"\u003Cp>What is the difference between Sanger sequencing and next-generation sequencing (NGS)?\u003C\u002Fp>","\u003Cp>Sanger sequencing reads one DNA target at a time with very high accuracy. NGS reads enormous amounts of DNA in parallel, which is far faster for large projects but has a slightly higher error rate per read. In practice they work together: NGS scans broadly, and Sanger is used to confirm the important findings. This is why Sanger is often called the gold standard.\u003C\u002Fp>",{"question":291,"answer":292},"\u003Cp>Is Sanger sequencing still used today?\u003C\u002Fp>","\u003Cp>Yes. Even though NGS handles large-scale sequencing, Sanger remains the reference method for reading a single target accurately. It is routinely used to confirm variants found by NGS, to check specific known mutations, to verify cloned genes and plasmids, and to identify bacteria from genes such as 16S rRNA.\u003C\u002Fp>",{"question":294,"answer":295},"\u003Cp>How long a sequence can Sanger sequencing read?\u003C\u002Fp>","\u003Cp>A single Sanger run typically reads about 500 to 1000 bases of high-quality sequence. For longer stretches, several overlapping runs are combined, or a higher-throughput method is used instead.\u003C\u002Fp>",{"question":297,"answer":298},"\u003Cp>Why is only a small amount of ddNTP used in the reaction?\u003C\u002Fp>","\u003Cp>If there were too much ddNTP, almost every strand would stop at the very first position and only the first base could be read. Keeping ddNTPs rare means most positions are usually filled by normal nucleotides, so across millions of strands every position is terminated in some fraction of the fragments. That produces a complete set of fragment lengths and lets the whole sequence be read.\u003C\u002Fp>",[215],{"enabled":301,"threads":302,"total":303},true,[],0,[305,311,318,325,331,336,341,346,351,354,361],{"slug":306,"name":43,"description":307,"image":308,"body":309,"postCount":310},"acharya-tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",510,{"slug":312,"name":313,"description":314,"image":315,"body":316,"postCount":317},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",88,{"slug":319,"name":320,"description":321,"image":322,"body":323,"postCount":324},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsushmita-baniya-1.png","Sushmita Baniya holds an M.Sc. in Medical Microbiology from Tribhuvan University (National College), with a research focus in Genetics and Molecular Biology. She is actively involved in teaching and research in the field of microbiology.",26,{"slug":326,"name":327,"description":321,"image":328,"body":329,"postCount":330},"samikshya-acharya","Samikshya Acharya","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsamikshya-acharya.jpeg","Samikshya Sharma completed her postgraduate studies in Medical Microbiology at the Central Department of Microbiology, Tribhuvan University, Nepal. She contributes to Microbeonline with the goal of making foundational and clinical microbiology concepts clear and useful for students in medical, laboratory science, and allied health programs.",20,{"slug":332,"name":333,"description":321,"image":42,"body":334,"postCount":335},"alisha-tripathi","Alisha Tripathi","Alisha Tripathi holds an M.Sc. in Medical Microbiology from National College, Tribhuvan University. With over a year of teaching experience, her academic interests span Molecular Biology, Immunology, and Genetics.",6,{"slug":337,"name":266,"description":338,"image":42,"body":339,"postCount":340},"aastha-shrestha"," Author \u002F Contributor","Aastha Shrestha is a Biotechnology graduate with an M.Sc. from National College, Tribhuvan University. Her academic interests center on Molecular Biology and Immunology; two fields that are increasingly converging in modern diagnostic and clinical microbiology. \n\nShe contributes to Microbeonline with the goal of making complex concepts in these areas approachable and exam-relevant for students across medical, biotechnology, and laboratory science programs.",9,{"slug":342,"name":343,"description":344,"image":42,"body":42,"postCount":345},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":347,"name":180,"description":321,"image":348,"body":349,"postCount":350},"srijana-khanal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsrijana-khanal-1.png","Srijana Khanal is a microbiology educator with nearly a decade of teaching experience, including her role as faculty in the Microbiology Department at National College, NIST. \n\nHer time in the classroom has given her a clear sense of where students struggle and what explanations actually work, a perspective that directly shapes how she writes.\n\nHer academic interests span Immunology, Genetics, Basic Sciences, and Research Methodology, and she brings the same rigor to her writing that she brought to teaching. Alongside academic writing, she has a passion for creative writing -- an instinct that shows in her ability to make dense scientific material readable without sacrificing accuracy.\n\nShe contributes to Microbeonline to extend her teaching reach beyond the classroom, helping medical and laboratory science students across the region build a stronger foundation in microbiology.",15,{"slug":352,"name":353,"description":344,"image":42,"body":42,"postCount":345},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":355,"name":356,"description":357,"image":358,"body":359,"postCount":360},"nisha-rijal","Nisha Rijal","Microbiologist and AMR Specialist Kathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fnisha-rijal-1.png","Nisha Rijal is a microbiologist with nearly 15 years of frontline diagnostic and surveillance experience at the National Public Health Laboratory (NPHL), national reference laboratory under the Department of Health Services, Nepal. She currently works as an AMR Support Officer at the World Health Organization (WHO), Nepal, where her work focuses on strengthening antimicrobial resistance surveillance systems and translating AMR data into actionable public health response.\n\nHer research, published in peer-reviewed journals and cited over 220 times, spans some of the most clinically significant infectious disease challenges in Nepal and South Asia: antimicrobial resistance trends in *Vibrio cholerae* across an 11-year national surveillance dataset, sero-epidemiology of scrub typhus in patients with acute febrile illness, lower respiratory tract infections in HIV-positive patients, and gonococcal resistance surveillance. She was a contributor to Nepal's National Antimicrobial Resistance Containment Action Plan, a foundational policy document for AMR governance in Nepal. You can find list of [Nisha Rijal's article here in Google Scholar.](https:\u002F\u002Fscholar.google.com\u002Fcitations?user=N-Ruq54AAAAJ&hl=en)\n\nThis depth of experience is visible in her writing at Microbeonline. Her 53 published articles cover bacteriology, parasitology, mycology, immunology, and laboratory techniques, and are consistently among the most detailed and clinically grounded content on the site. She brings to every article the same standard that national reference laboratory work demands: methodological precision, awareness of real diagnostic constraints, and an understanding of what results actually mean for patient care in resource-limited settings.\n\nHer areas of particular expertise include antimicrobial susceptibility testing and resistance mechanism detection, quality assurance in clinical microbiology, and laboratory-based infectious disease surveillance.\n\n---\n\n*Nisha Rijal contributes to Microbeonline in a personal capacity. Her views and writing do not represent the positions of the World Health Organization or any other institution.*",55,{"slug":362,"name":363,"description":364,"image":365,"body":366,"postCount":345},"padma-shrestha","Padma Shrestha","Author","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fpadma-shrestha.png","Padma Shrestha is from Kathmandu, Nepal. She has completed Masters degree in Medical microbiology from Tribhuvan University. She has great interest in Microbiology and Molecular Biology.",[368,375,381,385,390,395,398,402,406,411,415,420,424,429,434,439,443,447,452,456,460,464,468,472,476,480,484,488,493,498,503,507,511,516,520,524,528,532,536,540,544,548,552,555,559,564,568,572,577,581,585,589,593,597,601,606,610,614,618,622,626,630,634,638,642,646,650,653,656,660,663,666,669,672,675,678,681,684,687,690,693,696,699,702,705,708],{"slug":369,"name":370,"description":371,"image":372,"body":373,"postCount":374},"gram-negative-cocci","Gram-Negative Cocci and Coccobacilli","Neisseria, Moraxella, Haemophilus and related gram-negative coccal organisms","https:\u002F\u002Fassets.microbeonline.com\u002Ftags\u002Fgram-negative-cocci.png","# Gram Negative Cocci\n\nNeisseria gonorrhoeae, Neisseria meningitides, Moraxella catarrhalis, and other Neisseria spp. are clinically relevant gram-negative cocci.\n\nN. gonorrhoeae is the leading cause of sexually transmitted disease whereas N. meningitides is a leading cause of fatal bacterial meningitis.",14,{"slug":376,"name":377,"description":378,"image":42,"body":379,"postCount":380},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":382,"name":383,"description":384,"image":42,"body":42,"postCount":380},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",{"slug":386,"name":387,"description":388,"image":42,"body":42,"postCount":389},"gram-negative-rods","Gram-Negative Rods (Other than Enterobacteriaceae)","\u003Cp>Gram negative rods other than members of Enterobacteriaceae family such as  Pseudomonas, Acinetobacter and related organisms\u003C\u002Fp>",5,{"slug":391,"name":392,"description":393,"image":42,"body":42,"postCount":394},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":261,"name":396,"description":397,"image":42,"body":42,"postCount":380},"Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":399,"name":400,"description":401,"image":42,"body":42,"postCount":380},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":403,"name":404,"description":405,"image":42,"body":42,"postCount":380},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":407,"name":408,"description":409,"image":42,"body":42,"postCount":410},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":412,"name":413,"description":414,"image":42,"body":42,"postCount":374},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":416,"name":417,"description":418,"image":42,"body":42,"postCount":419},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",22,{"slug":421,"name":422,"description":423,"image":42,"body":42,"postCount":374},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":425,"name":426,"description":427,"image":42,"body":42,"postCount":428},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":430,"name":431,"description":432,"image":42,"body":42,"postCount":433},"specimen-collection-transport","Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":435,"name":436,"description":437,"image":42,"body":42,"postCount":438},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",21,{"slug":440,"name":441,"description":42,"image":42,"body":442,"postCount":335},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":444,"name":445,"description":42,"image":42,"body":446,"postCount":428},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":448,"name":449,"description":450,"image":42,"body":451,"postCount":410},"electrophoresis","Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":79,"name":453,"description":454,"image":42,"body":455,"postCount":335},"PCR Techniques","Information about various types of Polymerase Chain Reaction Techniques ","More detailed information about various types of Polymerase Chain Reaction Techniques ",{"slug":457,"name":458,"description":459,"image":42,"body":42,"postCount":335},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":461,"name":462,"description":463,"image":42,"body":42,"postCount":335},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":465,"name":466,"description":467,"image":42,"body":42,"postCount":335},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":469,"name":470,"description":471,"image":42,"body":42,"postCount":438},"immunoassays","Immunoassays","You will get information about all the diagnostic tests that rely on the specific binding between an antigen and an antibody to detect or quantify a substance.",{"slug":473,"name":474,"description":475,"image":42,"body":42,"postCount":410},"biosafety-levels","Biosafety levels ","Articles related to Biosafety Levels",{"slug":477,"name":478,"description":479,"image":42,"body":42,"postCount":389},"environmental-factors","Environmental Factors ","In this case we are talking about growth requirements of microorganisms with deep dive in environmental factors that affect the growth. ",{"slug":481,"name":482,"description":483,"image":42,"body":42,"postCount":335},"pipette","Pipette","Posts related with Pipette. ",{"slug":485,"name":486,"description":487,"image":42,"body":42,"postCount":410},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":489,"name":490,"description":491,"image":42,"body":42,"postCount":492},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":494,"name":495,"description":496,"image":42,"body":42,"postCount":497},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":499,"name":500,"description":501,"image":42,"body":42,"postCount":502},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",3,{"slug":504,"name":505,"description":506,"image":42,"body":42,"postCount":410},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":508,"name":509,"description":510,"image":42,"body":42,"postCount":428},"microbial-curiosities","Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":512,"name":513,"description":514,"image":42,"body":42,"postCount":515},"bacterial-culture-media","Bacterial Culture Media","Posts related to Bacterial Culture Media. ",23,{"slug":517,"name":518,"description":519,"image":42,"body":42,"postCount":335},"fungal-culture-media","Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":521,"name":522,"description":523,"image":42,"body":42,"postCount":389},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":525,"name":526,"description":527,"image":42,"body":42,"postCount":428},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":529,"name":530,"description":531,"image":42,"body":42,"postCount":492},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":533,"name":534,"description":535,"image":42,"body":42,"postCount":335},"dimorphic-fungi","Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":537,"name":538,"description":539,"image":42,"body":42,"postCount":410},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":541,"name":542,"description":543,"image":42,"body":42,"postCount":389},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":545,"name":546,"description":547,"image":42,"body":42,"postCount":340},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":549,"name":550,"description":551,"image":42,"body":42,"postCount":410},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":553,"name":554,"description":42,"image":42,"body":42,"postCount":502},"haemophilus","Haemophilus",{"slug":556,"name":557,"description":558,"image":42,"body":42,"postCount":335},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":560,"name":561,"description":562,"image":42,"body":42,"postCount":563},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",13,{"slug":565,"name":566,"description":567,"image":42,"body":42,"postCount":374},"fungal-diagnostics","Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":569,"name":570,"description":571,"image":42,"body":42,"postCount":389},"laboratory-storage-and-preservation","Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":573,"name":574,"description":575,"image":42,"body":576,"postCount":335},"laboratory-heating-equipment","Laboratory Heating Equipment","A guide to laboratory heating equipment, including hot plates, water baths, Bunsen burners, incubators, and dry baths, and how to choose the right one for each task.","Laboratory heating equipment covers the instruments that warm, melt, incubate, or sterilize samples and media in a microbiology laboratory. Each one delivers heat differently. \n\nA hot plate gives high, direct, dry heat; a water bath gives gentle, even, wet heat up to about 100°C; a Bunsen burner gives an open flame for rapid, very high heat; an incubator holds cultures at a steady temperature over hours or days; and a dry bath heats small tubes without water. Choosing the right one depends on the temperature you need, how precise it must be, and whether the sample can tolerate direct or open-flame heat.\n\nThe articles below cover each piece of heating equipment in detail, including its parts, working principle, uses, and the mistakes that most often go wrong at the bench.",{"slug":578,"name":579,"description":580,"image":42,"body":42,"postCount":340},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":582,"name":583,"description":584,"image":42,"body":42,"postCount":340},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":586,"name":587,"description":588,"image":42,"body":42,"postCount":335},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":590,"name":591,"description":592,"image":42,"body":42,"postCount":345},"tests-for-gram-positive-cocci","Biochemical Tests for Gram Positive Cocci","This is the lists of Biochemical Tests that are used for Gram Positive Cocci. ",{"slug":594,"name":595,"description":596,"image":42,"body":42,"postCount":428},"bacterial-staining-technique","Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":598,"name":599,"description":600,"image":42,"body":42,"postCount":438},"enzyme-tests","Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":602,"name":603,"description":604,"image":42,"body":42,"postCount":605},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",11,{"slug":607,"name":608,"description":609,"image":42,"body":42,"postCount":389},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":611,"name":612,"description":613,"image":42,"body":42,"postCount":497},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":615,"name":616,"description":617,"image":42,"body":42,"postCount":394},"substrate-utilization","Substrate Utilization","\u003Cp>The test in which a non-sugar carbon\u002Fnitrogen source is used or degraded (citrate, malonate, decarboxylases, indole, PAD).\u003C\u002Fp>",{"slug":619,"name":620,"description":621,"image":42,"body":42,"postCount":502},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":623,"name":624,"description":625,"image":42,"body":42,"postCount":389},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":627,"name":628,"description":629,"image":42,"body":42,"postCount":410},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":631,"name":632,"description":633,"image":42,"body":42,"postCount":497},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":635,"name":636,"description":637,"image":42,"body":42,"postCount":389},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":639,"name":640,"description":641,"image":42,"body":42,"postCount":394},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":643,"name":644,"description":645,"image":42,"body":42,"postCount":335},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":647,"name":648,"description":649,"image":42,"body":42,"postCount":335},"genetic-code","Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":215,"name":651,"description":652,"image":42,"body":42,"postCount":410},"Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":654,"name":655,"description":42,"image":42,"body":42,"postCount":345},"colorimetric-assay","Colorimetric Assay ",{"slug":657,"name":658,"description":659,"image":42,"body":42,"postCount":389},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":661,"name":662,"description":42,"image":42,"body":42,"postCount":502},"blood-and-immune-cells","Blood and Immune Cells",{"slug":664,"name":665,"description":42,"image":42,"body":42,"postCount":389},"host-pathogen-interaction","Host Pathogen Interaction",{"slug":667,"name":668,"description":42,"image":42,"body":42,"postCount":497},"blood-culture","Blood Culture",{"slug":670,"name":671,"description":42,"image":42,"body":42,"postCount":497},"environmental-microbiology","Environmental microbiology ",{"slug":673,"name":674,"description":42,"image":42,"body":42,"postCount":410},"copromicroscopic-technique","Copromicroscopic Technique",{"slug":676,"name":677,"description":42,"image":42,"body":42,"postCount":502},"quality-control","Quality Control",{"slug":679,"name":680,"description":42,"image":42,"body":42,"postCount":410},"dermatophytes","Dermatophytes",{"slug":682,"name":683,"description":42,"image":42,"body":42,"postCount":502},"viral-hemorrhagic-fevers","Viral Hemorrhagic Fevers",{"slug":685,"name":686,"description":42,"image":42,"body":42,"postCount":497},"h2s-production","H2S Production",{"slug":688,"name":689,"description":42,"image":42,"body":42,"postCount":492},"water-quality-testing","Water Quality Testing",{"slug":691,"name":692,"description":42,"image":42,"body":42,"postCount":389},"virology-basics","Virology basics",{"slug":694,"name":695,"description":42,"image":42,"body":42,"postCount":497},"typing-methods","Typing Methods",{"slug":697,"name":698,"description":42,"image":42,"body":42,"postCount":502},"blotting-technique","Blotting Technique",{"slug":700,"name":701,"description":42,"image":42,"body":42,"postCount":497},"history-microbiology","History of Microbiology",{"slug":703,"name":704,"description":42,"image":42,"body":42,"postCount":335},"trematodes","Trematodes",{"slug":706,"name":707,"description":42,"image":42,"body":42,"postCount":497},"coccidian-parasites","Coccidian Parasites",{"slug":709,"name":710,"description":711,"image":42,"body":42,"postCount":374},"cell-structure","Cell Structure","\u003Cp>Articles related to Cell Structure. \u003C\u002Fp>"]