[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fbBuP9JvyTMvWAz_vihcstgG2pL3k7X4gtgK2W0dOOA8":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":247,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":308},[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":45,"draft":46,"category":47,"image":42,"body":48,"faq":49,"commentsClosed":46,"tags":80,"related":82,"comments":243},"polyacrylamide-gel-electrophoresis-page","Polyacrylamide Gel Electrophoresis (PAGE): Principle and Procedure","Polyacrylamide gel electrophoresis (PAGE) separates proteins by size. Learn why SDS is added, why the gel has a stacking and a resolving layer, how to choose the acrylamide percentage, and how SDS-PAGE underpins the Western blot.",null,"Samikshya Acharya","2023-03-19","2026-07-11",false,"lab-equipment","Look at the names of two HIV proteins: p24 and gp41. Students memorize them as arbitrary labels. They are not. The number in each name **is the protein's molecular weight in kilodaltons**. p24 is a 24 kDa protein. gp41 is a 41 kDa glycoprotein. Proteins across microbiology and immunology are named this way, and the naming comes directly from the technique in this article.\n\nWhen a protein is run on an SDS-PAGE gel, it does not separate by charge, because a detergent has coated every protein with the same charge. It does not separate by shape, because it has been reduced and boiled into a straight chain. It separates by one thing only: **size**. Large proteins crawl; small ones race ahead. Run a protein of unknown size beside a ladder of known sizes, and the distance it travels tells you its molecular weight.\n\nThat is the whole point of SDS-PAGE. It turns a mixed sample of proteins into a ruler. Every reagent in the protocol below exists to make one variable, size, the only variable that matters. Understand why each reagent is there and the procedure stops being a list to memorize.\n\nThis is also the first step of a Western blot: proteins are separated by size on the gel, transferred to a membrane, and probed with antibody. It is why the bands on a Western blot sit where they do, and it remains everyday practice, from Lyme disease serology to routine protein work in any laboratory that runs a Coomassie gel.\n\n**What is polyacrylamide gel electrophoresis (PAGE)?**\n\nPAGE is a vertical slab gel technique that separates proteins and small nucleic acids by driving them through a cross-linked polyacrylamide mesh under an electric field. The gel acts as a molecular sieve: smaller molecules pass through the pores easily and travel far, while larger molecules are held back.\n\nIn its most common form, **SDS-PAGE**, the detergent sodium dodecyl sulfate coats every protein with a uniform negative charge and a reducing agent unfolds it. Charge and shape are removed as variables, so proteins separate by molecular weight alone, and the distance a band travels is inversely proportional to the logarithm of its molecular weight.\n\nElectrophoresis is a method used to separate macromolecules according to their charge, size, and shape under an electric field. Depending on the format in which the separation is carried out, it may be performed as a slab gel technique or inside a narrow tube, as in capillary electrophoresis. Polyacrylamide gel electrophoresis (PAGE) is a slab gel technique, run in a vertical configuration.\n\nPolyacrylamide gel electrophoresis is a form of gel electrophoresis used in molecular biology, forensic chemistry, genetics, biochemistry, and biotechnology to separate biological macromolecules, primarily proteins and small nucleic acids, according to their electrophoretic mobility. It uses a cross-linked polyacrylamide mesh as the support matrix, which gives a much finer sieving action, and therefore much higher resolution, than agarose.\n\nThe most commonly used polyacrylamide gel electrophoresis for quantitative protein analysis is Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).\n\n## Polyacrylamide Gel\n\nThe polyacrylamide gel forms by polymerizing acrylamide and a crosslinking agent, i.e., N, N’-methylene-bis-acrylamide. It does not react with proteins and consists of pores and channels that allow the protein to move through it.\n\nTwo parameters characterize a polyacrylamide gel: the total monomer concentration (%T, in g\u002F100 ml) and the weight percentage of cross-linker (%C). Varying these two parameters regulates the pore size of the gel, which is how the gel is matched to the size range being separated. The relationship is inverse: a higher %T produces smaller pores, which resolve smaller molecules better.\n\n## Principle of Polyacrylamide Gel Electrophoresis (PAGE)\n\nPolyacrylamide gel electrophoresis is based on the principle that charged particles migrate to the electrode of the opposite sign under the influence of an electric field.\n\n![Principle of polyacrylamide gel electrophoresis - Principle of  polyacrylamide gel electrophoresis, Image source: DOI: 10.1016\u002FB978-0-12-803077-6.00012-6](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FSchematic-of-SDS-Page-electrophoresis-Polyacrylamide-two-part-gel-composed-of-a-stacking.jpg)Figure: Principle of polyacrylamide gel electrophoresis, Image source: DOI: 10.1016\u002FB978-0-12-803077-6.00012-6\n\nIn polyacrylamide gel electrophoresis, the sample (usually protein) is dissolved in a loading buffer containing denaturing agents (sodium dodecyl sulfate and β-mercaptoethanol), glycerol, and bromophenol blue. Sodium dodecyl sulfate is an anionic detergent. It denatures the protein and binds along the polypeptide chain at approximately one SDS molecule per two amino acid residues\n\nTherefore, the negative charge of SDS results in a net negative charge in the protein sample. Similarly, β-mercaptoethanol also denatures the protein sample by cleaving the disulfide bond.\n\nGlycerol increases the density of the sample so that it sinks to the bottom of the well during loading, rather than floating away into the running buffer. Bromophenol blue is a small, fast-migrating tracking dye. It does not stain the protein. It runs ahead of nearly all proteins as a visible dye front, so the operator can see how far the run has progressed and stop it before the smallest proteins run off the end of the gel.\n\nWhen the electric current passes through the electrophoretic chamber, the protein-sodium dodecyl sulfate complex starts moving toward the anode. Gel percentage is chosen to match the size of the proteins being separated. A low-percentage gel (4 to 8% acrylamide) has large pores, so large proteins can enter it and spread out, while small proteins run through almost unimpeded and are poorly resolved. A high-percentage gel (12 to 20% acrylamide) has small pores that hold back large proteins near the top of the gel, and resolve small proteins sharply.\n\n## Materials Required for PAGE\n\nVarious materials are required to conduct polyacrylamide gel electrophoresis, which include;\n\n- **Polyacrylamide gel:** It is the matrix that helps to separate proteins based on their size. It can be either prepared in the lab or can be purchased.\n- **Running buffer:** It varies based on sample type. Its primary function is to allow the conduction of current across the gel.\n- **Protein or nucleic acid sample:** The primary sample needed to separate based on its molecular weight.\n- **Staining and de-staining reagent:** Coomassie stain solution is mainly helps to stain protein bands after electrophoresis. In contrast, the de-staining reagent (prepared by mixing methanol, acetic acid, and water) helps to de-stain the gel.\n\n**Essentials of electrophoresis:**\n\n- **Gel plate:** It is the plate that holds the polymerized gel in an electrophoresis chamber.\n- **Comb:** A toothed plate inserted into the liquid stacking gel before it sets. Once the gel polymerizes, the comb is removed, leaving behind the wells into which samples are loaded.\n- **Electrophoresis chamber:** Polyacrylamide gel is packed within a running buffer, and electrophoresis is carried out.\n- **Protein ladder:** It is a reference protein ladder with known size. It helps to confirm the molecular weight of the protein of interest.\n- **Power supply:** It supports converting AC to DC, which is essential to create an electric field.\n\n## Procedure involved in PAGE\n\nThe procedure involved while operating polyacrylamide gel electrophoresis is;\n\n### Sample preparation\n\n![Sample preparation - Sample preparation](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FSDS-PAGE_sample.png)Figure: Sample preparation\n\n1. The sample can be either protein or nucleic acid.\n2. The sample is mixed with a loading buffer containing denaturing agents (SDS and β-mercaptoethanol), glycerol, and bromophenol blue. For nucleic acids, urea is used as the denaturing agent instead of SDS.\n3. Heating the samples with denaturing agents and mercaptoethanol for 5-10 minutes further enhances the denaturation.\n\n### Preparation of polyacrylamide gel\n\n![Preparation of polyacrylamide gel - Preparing of the polyacrylamide gel](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FSDS-PAGE_acrylamide_stock.png)Figure: Preparing of the polyacrylamide gel\n\n1. The gel mixture comprises acrylamide, bis-acrylamide, a buffer at the appropriate pH, and an optional denaturant (SDS for protein, urea for nucleic acid).\n2. Polymerization requires two further reagents. Ammonium persulfate (APS) is the free-radical initiator, and TEMED (N,N,N',N'-tetramethylethylenediamine) is the catalyst that accelerates radical formation. Both are added last, immediately before pouring, because the gel begins to set as soon as they are mixed in.\n3. Two gels are cast. The separating (resolving) gel at pH 8.8 is poured first, between the glass plates. Water-saturated isobutanol is gently layered on top of it. This gives a flat gel surface and, importantly, excludes atmospheric oxygen, which inhibits acrylamide polymerization.\n4. Once the separating gel has set, the isobutanol is poured off and the stacking gel at pH 6.8 is poured on top. The comb is inserted into the still-liquid stacking gel.\n5. After the stacking gel polymerizes, the comb is withdrawn, leaving wells. The assembled unit is now called a gel cassette.\n\n![Preparation of gel cassette - Preparation of gel cassette](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FSDS-PAGE_Acrylamide_gel.png)Figure: Preparation of gel cassette\n\n### Electrophoresis\n\n1. Depending on the sample type, the use of different buffer systems can help to run polyacrylamide gel electrophoresis.\n2. The buffer used at the cathode or anode might be the same or different.\n3. The gel cassette is removed from the casting stand, placed in the electrode assembly, and secured in the clamp stand.\n4. Then, 1X running buffer is poured into the electrophoresis chamber.\n5. Each well is then loaded with a protein sample. Similarly, marker protein is also loaded into a single well of gel.\n6. The tank is then covered with a lid, and the sample can run at 30mA for about 1 hour.\n\n![Running of polyacrylamide gel electrophoresis - Running of polyacrylamide gel electrophoresis](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FSDS-PAGE_Electrophoresis.png)Figure: Running of polyacrylamide gel electrophoresis\n\n### Detection\n\nFollowing electrophoresis, the gel is stained so the bands become visible and can be compared against the ladder. Coomassie brilliant blue is used for proteins. Ethidium bromide has traditionally been used for nucleic acids, but it is a mutagen, and safer intercalating stains such as SYBR Gold or GelRed are now preferred where available.\n\n![Polyacrylamide gel after staining with Coomassie blue - Polyacrylamide gel after staining with Coomassie blue](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002F200px-Coomassie_blue_stained_gel.png)Figure: Polyacrylamide gel after staining with Coomassie blue\n\n## Applications of Polyacrylamide Gel Electrophoresis (PAGE)\n\nPolyacrylamide gel electrophoresis is applicable in a wide range of that includes;\n\n 1. It helps to determine the purity of samples.\n 2. It is also helpful in determining the molecular weight of protein.\n 3. PAGE helps to quantify the proteins.\n 4. It helps in monitoring changes in protein in body fluids.\n 5. PAGE is useful in peptide mapping.\n 6. It is useful to estimate the purity of the protein and nucleic acid.\n 7. SDS-PAGE is the first step of every [Western blot.](https:\u002F\u002Fmicrobeonline.com\u002Fwestern-blot-technique-principle-procedures-advantages-and-disadvantages\u002F) Proteins are separated by size on the gel, transferred onto a membrane, and then probed with a specific antibody. The band's position on the gel is what identifies the protein.\n 8. It is useful for the detection of protein ubiquitination.\n 9. PAGE is helpful to analyze the size and number of polypeptide subunits.\n10. It underpins Western blot serology. In the historical HIV confirmatory Western blot, patient antibodies were detected against viral proteins separated by SDS-PAGE, and the proteins are named for the molecular weights at which they resolve: p24 (24 kDa capsid protein), gp41 and gp120 (41 and 120 kDa envelope glycoproteins). The HIV algorithm has since replaced Western blot with an antigen\u002Fantibody immunoassay followed by an HIV-1\u002FHIV-2 differentiation assay, but Western blot remains standard in the two-tier serology of Lyme disease, and SDS-PAGE remains its first step.\n\n## Advantages of Polyacrylamide Gel Electrophoresis (PAGE)\n\nPolyacrylamide gel electrophoresis consists of the following benefits:\n\n1. It helps to determine the molecular weight, as migration is directly proportional to the molecular weight.\n2. It is a sensitive technique, capable of detecting small quantities of protein.\n3. It can provide results even with a small amount of sample.\n4. It consists of chemically crosslinked stable gel.\n5. The sample recovered from the gel is exceptionally pure.\n6. It is best for separating proteins of low molecular weight.\n\n## Disadvantages of Polyacrylamide Gel Electrophoresis (PAGE)\n\nDespite the benefits, polyacrylamide gel electrophoresis has some drawbacks which are as follows:\n\n1. Unpolymerized acrylamide monomer is a potent neurotoxin and a probable human carcinogen. It is absorbed through the skin, so it must be handled with gloves, and powder must be weighed with care to avoid inhaling dust.\n2. Preparation of gel is time-consuming, and electrophoresis also takes a longer time.\n3. It requires a higher budget to operate.\n4. The preparation of a new gel for each test is necessary.\n\n## Precautions of Polyacrylamide Gel Electrophoresis (PAGE)\n\nWhile performing polyacrylamide gel electrophoresis one should consider following precautionary measure:\n\n1. Routine care should be exercised in handling buffers and samples to avoid accidental ingestion, needle stick, etc.\n2. Acrylamide and bisacrylamide are highly toxic monomers of polyacrylamide gel. Therefore, the use of gloves for handling polyacrylamide gel.\n3. A precise amount of polyacrylamide monomers should be weighed to obtain desired pore size.\n4. Always wear gloves, goggles, and a lab coat while handling samples and buffers.\n\n## Differences Between Agarose Gel and Polyacrylamide Gel Electrophoresis (PAGE)\n\nAlthough both techniques are used for separation purposes, they have some differences. The differences between [agarose gel electrophoresis](\u002Fagarose-gel-electrophoresis\u002F) and polyacrylamide gel electrophoresis are given below;\n\n| Polyacrylamide gel electrophoresis (PAGE) | Agarose gel electrophoresis |\n| --- | --- |\n| In polyacrylamide gel electrophoresis, polyacrylamide gel separates macromolecules, i.e., proteins of size five kDa to 250 kDa. Similarly, it can also isolate DNA of 5- 500 bp size. | In agarose gel electrophoresis, agarose gel separates DNA, RNA, and protein. It can isolate DNA about 50-20,000 bp in size. |\n| The run configuration of polyacrylamide gel electrophoresis is vertical. | The run configuration of agarose gel electrophoresis is horizontal. |\n| Unpolymerized acrylamide monomer is a potent neurotoxin and probable carcinogen. The polymerized gel is far safer, but may contain residual monomer, so gloves are worn. | Agarose is non-toxic in both powder and gel form. |\n| It gives better resolution than agarose gel. | It gives poor resolution than polyacrylamide gel. |\n| Gels must be cast between glass plates by chemical polymerization, which takes time, and the finished gel is thin and fragile. | Gels are poured from melted agarose in minutes, are physically robust, and the agarose can be re-melted and recast. |\n| It requires two layers of gel, i.e., staking and separating gel. | It only requires a single layer of agarose gel. |\n\n**References**\n\n1. Laemmli UK. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970;227(5259):680-685. doi:10.1038\u002F227680a0\n2. Wilson K, Walker J. Principles and Techniques of Biochemistry and Molecular Biology. 8th ed. Cambridge: Cambridge University Press; 2018. Chapter: Electrophoretic Techniques.\n3. Westermeier R. Electrophoresis in Practice: A Guide to Methods and Applications of DNA and Protein Separations. 5th ed. Weinheim: Wiley-VCH; 2016.\n4. Ornstein L. Disc electrophoresis I: Background and theory. Annals of the New York Academy of Sciences. 1964;121(2):321-349.\n5. Davis BJ. Disc electrophoresis II: Method and application to human serum proteins. Annals of the New York Academy of Sciences. 1964;121(2):404-427.",[50,53,56,59,62,65,68,71,74,77],{"question":51,"answer":52},"Why is SDS added in SDS-PAGE?","SDS is an anionic detergent that unfolds the protein and binds along the polypeptide chain at a roughly constant ratio of about one SDS molecule per two amino acid residues. This gives every protein a negative charge proportional to its length, so that charge per unit mass becomes the same for all proteins. With the charge variable removed, migration depends on size alone, and the distance a band travels can be read directly as a molecular weight.",{"question":54,"answer":55},"Why does an SDS-PAGE gel have two layers?","The upper stacking gel (pH 6.8, large pores) does no separating. Its job is to compress proteins scattered throughout the depth of the loading well into a single thin disc, using a discontinuous buffer system in which slow-moving glycine trails and fast-moving chloride leads, sandwiching the proteins between them. When the disc reaches the lower resolving gel (pH 8.8, small pores), glycine ionizes and overtakes, the sandwich collapses, and all proteins begin separating from the same starting line. Without a stacking gel, every band would be a smear.",{"question":57,"answer":58},"What is the difference between native PAGE and SDS-PAGE?","SDS-PAGE denatures the protein with SDS and a reducing agent, so separation is by size alone and the protein is no longer functional. Native PAGE uses neither, so the protein retains its fold, subunits, and intrinsic charge, and separation depends on charge, size, and shape together. Use SDS-PAGE to measure the size of a polypeptide chain, and native PAGE to study a protein that must remain active or intact.",{"question":60,"answer":61},"How do I choose the acrylamide percentage?","Match the pore size to the size of your target. A low-percentage gel (4 to 8%) has large pores and resolves large proteins, while small proteins run straight through. A high-percentage gel (12 to 20%) has small pores that resolve small proteins sharply while large proteins barely enter the gel. Higher percentage does not mean better resolution in general; it means better resolution of smaller molecules.",{"question":63,"answer":64},"Which direction do proteins move in SDS-PAGE, and why?","Toward the anode, the positive electrode. SDS coats every protein with a strong negative charge, so all proteins become anions and are attracted to the positive electrode. This is why SDS-PAGE gels are run vertically with the anode at the bottom.",{"question":66,"answer":67},"What is the role of β-mercaptoethanol, and how is it different from SDS?","They denature different things. SDS unfolds the polypeptide chain and coats it with charge, but it cannot break covalent disulfide bonds. β-mercaptoethanol is a reducing agent that cleaves those bonds, separating proteins into their individual polypeptide chains. Immunoglobulin G, for example, runs as a single band of about 150 kDa without a reducing agent, and splits into heavy chains of about 50 kDa and light chains of about 25 kDa when β-mercaptoethanol is added.",{"question":69,"answer":70},"What do APS and TEMED do?","Ammonium persulfate (APS) is the free-radical initiator that starts acrylamide polymerization, and TEMED is the catalyst that accelerates radical formation from APS. Both are added immediately before the gel is poured, because polymerization begins as soon as they are mixed in. Oxygen inhibits polymerization, which is why water-saturated isobutanol is layered over the resolving gel to exclude air.",{"question":72,"answer":73},"Is polyacrylamide gel toxic?","Unpolymerized acrylamide monomer is a potent neurotoxin and a probable human carcinogen, and it is absorbed through the skin, so the powder and the unset gel solution must be handled with gloves. Once polymerized, the gel itself is far less hazardous, but it may contain traces of residual monomer, so gloves are worn when handling gels as well.",{"question":75,"answer":76},"What is the tracking dye in SDS-PAGE?","Bromophenol blue, not bromothymol blue. It is a small, fast-migrating dye that runs ahead of nearly all proteins, marking the dye front. It does not stain the proteins. When the dye front approaches the bottom of the gel, the run is stopped so that the smallest proteins do not run off the end.",{"question":78,"answer":79},"How is SDS-PAGE related to the Western blot?","SDS-PAGE is the first step of a Western blot. Proteins are separated by molecular weight on the gel, transferred to a membrane, and then probed with antibodies. Because separation is by size alone, the position of a band on the membrane identifies the protein. This is why HIV proteins carry names such as p24, gp41, and gp120: the numbers are the molecular weights in kilodaltons at which those proteins resolve.",[81],"electrophoresis",[83,117,155,194,201,236],{"slug":84,"title":85,"description":86,"seoTitle":42,"seoDescription":42,"author":87,"createdDate":88,"lastUpdatedDate":89,"draft":46,"category":47,"image":42,"faq":90,"tags":115},"western-blot-technique-principle-procedures-advantages-and-disadvantages","Western Blot Technique: Principle, Procedure, Interpretation, Advantages","\u003Cp>Western blot explained for students: full step-by-step procedure, how to read the bands, HIV result interpretation, plus advantages and disadvantages.\u003C\u002Fp>","Aastha Shrestha","2017-05-12","2026-08-25",[91,94,97,100,103,106,109,112],{"question":92,"answer":93},"\u003Cp>What is the western blot technique used for?\u003C\u002Fp>","\u003Cp>It identifies a specific protein within a mixture and confirms both its presence and its molecular weight. It is used in research to study proteins and in diagnosis to confirm certain infections, including as a former confirmatory test for HIV and a definitive test for conditions like Creutzfeldt-Jakob disease and Lyme disease.\u003C\u002Fp>",{"question":95,"answer":96},"\u003Cp>What is the principle of western blotting?\u003C\u002Fp>","\u003Cp>Proteins are first separated by size using gel electrophoresis (SDS-PAGE), then transferred to a membrane, and finally detected using an antibody that binds only the target protein. Separation by size plus antibody-based detection together make the result specific.\u003C\u002Fp>",{"question":98,"answer":99},"\u003Cp>What are the steps of western blotting?\u003C\u002Fp>","\u003Cp>Five stages: sample preparation (lyse cells, denature proteins), gel electrophoresis (separate by size), transfer (move proteins to a membrane), immunoblotting (block, then probe with primary and secondary antibodies), and detection (produce a visible signal, usually light via ECL).\u003C\u002Fp>",{"question":101,"answer":102},"\u003Cp>Why is it called immunoblotting?\u003C\u002Fp>","\u003Cp>Because an antibody (immuno) is used to detect the target protein on the blot. The two names, western blot and immunoblotting, mean the same technique.\u003C\u002Fp>",{"question":104,"answer":105},"\u003Cp>How do you read a western blot result?\u003C\u002Fp>","\u003Cp>Check the controls to confirm the run is valid, locate each band against the molecular weight ladder to identify the protein, and check whether the band pattern meets the rule for a positive result. For HIV, a positive result needs at least two of the bands p24, gp41, and gp120\u002F160.\u003C\u002Fp>",{"question":107,"answer":108},"\u003Cp>What does an indeterminate western blot mean?\u003C\u002Fp>","\u003Cp>Some bands are present, but the pattern does not meet the rule for a positive result. It cannot be called positive or negative. It can occur in very early infection before the full antibody response develops, or as a non-specific reaction. It is followed up with repeat or additional testing, not reported as a diagnosis.\u003C\u002Fp>",{"question":110,"answer":111},"\u003Cp>Is western blot still used to confirm HIV?\u003C\u002Fp>","\u003Cp>It was the standard confirmatory test for years and is still used in some laboratories and national programs. In the United States, since 2014 the CDC algorithm has replaced it with a rapid HIV-1\u002FHIV-2 antibody differentiation assay, because the western blot missed early infections and misclassified some HIV-2 cases.\u003C\u002Fp>",{"question":113,"answer":114},"\u003Cp>What is the difference between the primary and secondary antibody?\u003C\u002Fp>","\u003Cp>The primary antibody binds the target protein specifically but carries no signal. The secondary antibody binds the primary antibody and carries the enzyme (such as HRP) that produces the detectable signal. The primary aims; the secondary lights up.\u003C\u002Fp>",[116],"blotting-technique",{"slug":118,"title":119,"description":120,"seoTitle":42,"seoDescription":42,"author":121,"createdDate":122,"lastUpdatedDate":89,"draft":46,"category":47,"image":42,"faq":123,"tags":154},"agarose-gel-electrophoresis","Agarose Gel Electrophoresis: Principle, Procedure, Results","Agarose gel electrophoresis separates DNA fragments from 100 bp to 25 kb by size. Learn the principle, how to cast and run a gel, why supercoiled plasmid runs faster than linear DNA, and how to read a PCR gel against a DNA ladder.","Acharya Tankeshwar","2019-09-13",[124,127,130,133,136,139,142,145,148,151],{"question":125,"answer":126},"Does agarose gel electrophoresis separate DNA by size or by charge?","By size. Charge determines the direction of travel, because DNA's phosphate backbone is negatively charged and every fragment therefore migrates toward the anode. But DNA has a uniform charge-to-mass ratio, so every fragment experiences the same pull per unit mass, and charge separates nothing. The sieving action of the agarose mesh does all the separating, which is why migration distance reports fragment size.",{"question":128,"answer":129},"Why does DNA move toward the anode?","The phosphate backbone of DNA carries a negative charge at every pH used in the laboratory, making DNA an anion. Anions are attracted to the positive electrode, which is the anode. Unlike proteins, DNA has no isoelectric point to consider, so it always migrates in the same direction.",{"question":131,"answer":132},"What size range can agarose gel electrophoresis resolve?","Roughly 100 base pairs to 25 kilobases, depending on the agarose concentration. Fragments smaller than about 100 bp are better resolved by polyacrylamide gel electrophoresis, and fragments larger than about 25 kb require pulsed-field gel electrophoresis.",{"question":134,"answer":135},"Why does my plasmid preparation show three bands on the gel?","Because a circular plasmid exists in three conformations, and the gel separates by effective size rather than base-pair count. Supercoiled plasmid is tightly wound and compact, so it migrates fastest. Open circular (nicked) plasmid is a relaxed floppy loop with a large effective radius, so it snags in the mesh and migrates slowest. Linear plasmid runs in between. All three contain the same number of base pairs. Three bands from one preparation is normal, not a sign of contamination.",{"question":137,"answer":138},"How do I choose the agarose concentration?","Match the pore size to the fragment size. A low-percentage gel (around 0.5 to 0.8%) has large pores and resolves large fragments, while small fragments run through almost unimpeded. A high-percentage gel (1.5 to 2%) has small pores that resolve small fragments sharply while holding large fragments near the well. Higher percentage does not mean better resolution in general, only better resolution of smaller fragments.",{"question":140,"answer":141},"What is the difference between TAE and TBE buffer?","TAE (Tris-acetate-EDTA) has a lower buffering capacity and will exhaust during long runs, but it resolves large fragments well and the DNA recovered from a TAE gel is clean enough for downstream enzymatic work. TBE (Tris-borate-EDTA) has a much higher buffering capacity and gives sharper resolution of small fragments, but borate inhibits many enzymes and carries over into extracted DNA. Use TAE if you plan to cut the band out and use the DNA, and TBE if you only need to visualize it.",{"question":143,"answer":144},"What is a DNA ladder and why is it needed?","A DNA ladder is a mixture of DNA fragments of known sizes, run in a lane alongside the samples. It converts the height of a band into a number of base pairs. Without a ladder, the position of a band carries no information, because migration distance depends on the gel percentage, the voltage, and the run time.",{"question":146,"answer":147},"My PCR gel shows no band in the patient lane. Is that a negative result?","Only if the positive control produced a band. If the positive control is also blank, the reaction itself failed and the patient's lane carries no information. Likewise, if the negative control shows a band, the run is contaminated and no lane on that gel can be trusted. The controls are always read before the patient's sample.",{"question":149,"answer":150},"What do the dyes in the loading buffer do?","\u003Cp>Loading dye serves three purposes. Glycerol makes the sample dense enough to sink to the bottom of the well instead of drifting into the buffer. The color makes loading easier to see. And the tracking dyes migrate at predictable rates, marking how far the run has progressed. In a 1% agarose gel, bromophenol blue migrates at approximately the position of a 300 to 500 bp fragment and xylene cyanol at approximately 4 kb.\u003C\u002Fp>",{"question":152,"answer":153},"Is ethidium bromide dangerous, and what can be used instead?","Ethidium bromide intercalates into DNA and is a suspect mutagen and carcinogen, so it requires gloves and regulated disposal. Safer alternatives include SYBR Gold and SYBR Green, which are highly sensitive but expensive, and methylene blue or crystal violet, which are much safer but considerably less sensitive. A separate hazard is the short-wave ultraviolet light used to visualize ethidium bromide, which nicks DNA. If the band is to be excised for cloning, use a long-wave ultraviolet or blue-light transilluminator.",[81],{"slug":156,"title":157,"description":158,"seoTitle":42,"seoDescription":42,"author":159,"createdDate":160,"lastUpdatedDate":161,"draft":46,"category":47,"image":42,"faq":162,"tags":193},"cellulose-acetate-electrophoresis","Cellulose Acetate Electrophoresis: Principle and Application","Cellulose acetate electrophoresis separates serum proteins and hemoglobin variants by net charge at alkaline pH. Learn the principle, why Hb S co-migrates with Hb D and Hb G, and why a sickle cell result must be confirmed at acid pH.","Ashma Shrestha","2022-12-25","2026-08-24",[163,166,169,172,175,178,181,184,187,190],{"question":164,"answer":165},"What is the principle of cellulose acetate electrophoresis?","Proteins are separated on a cellulose acetate membrane soaked in an alkaline buffer, usually pH 8.4 to 8.6. Because the membrane's pores are large compared with a protein, it does almost no sieving, so separation depends on net charge rather than on size. At this alkaline pH the buffer is above the isoelectric point of every serum protein, so all carry a net negative charge and migrate toward the anode. The greater the net negative charge, the further the protein travels.",{"question":167,"answer":168},"Does cellulose acetate electrophoresis separate proteins by their isoelectric point?","No. A protein at its isoelectric point carries no net charge and does not migrate at all. Separation occurs because the buffer pH is held above the isoelectric point of every protein, so all are negatively charged and all move. The isoelectric point determines how negatively charged a protein is at the working pH, and therefore how fast it travels, but the separation does not occur at the isoelectric point. Separating molecules at their isoelectric points is a different technique, called isoelectric focusing.",{"question":170,"answer":171},"Why is cellulose acetate used for hemoglobin rather than a gel?","Hemoglobin variants such as Hb A and Hb S differ by a single amino acid and are essentially identical in size. A sieving matrix such as agarose or polyacrylamide separates by size and therefore cannot distinguish them. The large pores of cellulose acetate mean the membrane contributes almost nothing mechanically, so the separation is driven purely by the charge difference that the amino acid substitution creates.",{"question":173,"answer":174},"In what order do hemoglobins migrate on alkaline cellulose acetate?","Toward the anode, fastest first: Hb A, then Hb F, then Hb S, then Hb C. In Hb S, the negatively charged glutamate at position 6 of the beta chain is replaced by a neutral valine, reducing the net negative charge, so Hb S lags behind Hb A. In Hb C that same glutamate is replaced by a positively charged lysine, so Hb C lags further still.",{"question":176,"answer":177},"Can sickle cell disease be diagnosed from an alkaline cellulose acetate strip alone?","No. At alkaline pH, Hb S co-migrates with Hb D, Hb G, and Hb Lepore, and Hb C co-migrates with Hb E, Hb O-Arab, and Hb A2. A band at the S position identifies a charge, not a hemoglobin. Confirmation requires electrophoresis on citrate agar at acid pH, around 6.0 to 6.2, where Hb S separates from Hb D and Hb G, supported by a sickle solubility test.",{"question":179,"answer":180},"How do you distinguish sickle cell trait from sickle cell disease on the strip?","Look for the Hb A band. Sickle cell trait shows two bands, with Hb A denser than Hb S in roughly a 60 to 40 ratio. Sickle cell disease shows no Hb A band at all, a dense Hb S band, and often a raised Hb F. The absence of Hb A is what makes the diagnosis. A recent blood transfusion can introduce a donor-derived Hb A band and obscure this.",{"question":182,"answer":183},"Why are newborn screening results written as FS or FAS?","Hemoglobin bands in newborn screening are reported in descending order of abundance, and a newborn still produces mostly fetal hemoglobin. FA is a normal newborn, FAS indicates sickle cell trait, and FS indicates sickle cell disease, because no Hb A is present.",{"question":185,"answer":186},"Why do gamma globulins appear behind the point of application?","Because of electroendosmosis. Fixed negative charges on the cellulose acetate attract cations from the buffer, and the resulting bulk flow of buffer moves toward the cathode. This flow opposes the anodal migration of the proteins. Albumin carries enough net charge to overcome it easily, but the gamma globulins, which are the least negatively charged fraction, are dragged back to or slightly past the origin.",{"question":188,"answer":189},"How are the bands visualized on a cellulose acetate strip?","The strip is stained with a protein dye such as Ponceau S, Amido Black, or Coomassie brilliant blue, then destained in dilute acetic acid to remove background. It is then cleared in a methanol or acetic acid mixture, which turns the cellulose acetate optically transparent, allowing the strip to be scanned directly in a densitometer for quantification and stored as a permanent record. Where the analytes are enzymes, a zymogram may be used instead, revealing bands by their enzymatic activity.",{"question":191,"answer":192},"Is cellulose acetate electrophoresis still used?","Yes. In well-resourced laboratories, HPLC and capillary electrophoresis have largely replaced it for hemoglobin variant analysis, because they are automated, quantitative, and resolve variants that co-migrate at alkaline pH. Cellulose acetate remains widely used where those instruments are unavailable, and it retains the advantages of being simple, rapid, and inexpensive.",[81],{"slug":195,"title":196,"description":196,"seoTitle":42,"seoDescription":42,"author":159,"createdDate":197,"lastUpdatedDate":198,"draft":46,"category":47,"image":42,"faq":199,"tags":200},"capillary-electrophoresis","Capillary Electrophoresis: Principle and Application","2022-12-16","2026-07-05",[],[81],{"slug":202,"title":203,"description":204,"seoTitle":42,"seoDescription":42,"author":205,"createdDate":206,"lastUpdatedDate":161,"draft":46,"category":47,"image":42,"faq":207,"tags":235},"electrophoresis-principles-types-and-uses","Electrophoresis: Principles, Types, and Uses","Electrophoresis separates charged molecules such as proteins and DNA by moving them through a gel in an electric field. Learn the principle, the factors that control mobility, the main types, and how serum protein electrophoresis detects multiple myeloma.","Srijana Khanal","2022-07-13",[208,211,214,217,220,223,226,229,232],{"question":209,"answer":210},"What is the basic principle of electrophoresis?","Charged molecules placed in an electric field migrate toward the electrode of opposite charge. Negatively charged molecules (anions) move toward the positive anode, and positively charged molecules (cations) move toward the negative cathode. Each molecule travels at a speed set by its electrophoretic mobility, which depends on its net charge, its size and shape, and the viscosity and pore size of the medium. Molecules separate only if their mobilities differ.",{"question":212,"answer":213},"Why does DNA always move toward the anode?","DNA carries a phosphate backbone that remains negatively charged at any pH used in the laboratory. Because it is always an anion, it is always attracted to the positive anode. Its charge-to-mass ratio is also nearly constant regardless of fragment length, which is why DNA fragments separate essentially by size alone.",{"question":215,"answer":216},"Which way does a protein move in electrophoresis?","It depends on the buffer pH relative to the protein's isoelectric point (pI). Above its pI the protein is net negative and moves toward the anode. Below its pI it is net positive and moves toward the cathode. At exactly its pI, its net charge is zero and it does not migrate.",{"question":218,"answer":219},"Why is electrophoresis called an incomplete form of electrolysis?","In electrolysis, ions travel all the way to the electrode and undergo discharge there. In electrophoresis the electric field is switched off while the molecules are still in transit, so they never reach the electrode. What matters is not the reaction at the electrode but how far each molecule traveled, because that distance is the separation.",{"question":221,"answer":222},"What is the difference between zone and moving boundary electrophoresis?","In zone electrophoresis the sample is applied as a narrow zone on a supporting medium such as paper, cellulose acetate, or a gel, and components resolve into discrete bands. In moving boundary electrophoresis the separation occurs in free solution with no supporting medium, and the components appear as moving boundaries rather than distinct bands. The classical example of the latter is the Tiselius apparatus.",{"question":224,"answer":225},"What are the main factors affecting electrophoretic mobility?","Inherent factors include the net charge of the molecule, its charge density, its molecular weight, and its size and shape. External factors include the applied voltage, current and power, the pore size and viscosity of the supporting medium, the temperature, and the pH of the buffer, which determines the net charge on ampholytes such as proteins.",{"question":227,"answer":228},"How is electrophoresis used to diagnose multiple myeloma?","Serum protein electrophoresis separates serum proteins into albumin and the alpha, beta, and gamma globulin fractions. Normal gamma globulins are produced by thousands of plasma cell clones with slightly different mobilities, so they form a broad band. In multiple myeloma a single malignant clone produces one identical immunoglobulin, and these identical molecules migrate together to produce a sharp, narrow monoclonal (M) band in the gamma region.",{"question":230,"answer":231},"Does electrophoresis separate molecules by size or by charge?","By both, because mobility depends on the ratio of net charge to size. SDS-PAGE deliberately removes the charge variable by coating every protein with a uniform negative charge proportional to its length, so that separation depends on size alone. Native gels, in contrast, separate molecules on the basis of charge and size together.",{"question":233,"answer":234},"Why is a larger pore size not always better?","Larger pores impede migration less, so molecules travel faster, but small molecules pass through almost unhindered and are therefore poorly resolved. The gel concentration is chosen to match the size range of interest: a low-percentage gel resolves large fragments, and a high-percentage gel resolves small ones.",[81],{"slug":237,"title":238,"description":239,"seoTitle":42,"seoDescription":42,"author":121,"createdDate":240,"lastUpdatedDate":89,"draft":46,"category":47,"image":42,"faq":241,"tags":242},"pulsed-field-gel-electrophoresis-pfge","Pulsed-Field Gel Electrophoresis (PFGE): Steps, Applications","Pulsed-field gel electrophoresis (PFGE) separates DNA fragments up to 10 Mb by switching the electric field between directions, forcing large molecules to reorient. Learn why pulsing works, the plug-based steps, and why PFGE was the gold standard for outbreak fingerprinting.","2019-09-16",[],[81],{"enabled":244,"threads":245,"total":246},true,[],0,[248,254,260,267,272,277,282,287,292,295,302],{"slug":249,"name":121,"description":250,"image":251,"body":252,"postCount":253},"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.*",480,{"slug":255,"name":159,"description":256,"image":257,"body":258,"postCount":259},"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.",79,{"slug":261,"name":262,"description":263,"image":264,"body":265,"postCount":266},"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":268,"name":43,"description":263,"image":269,"body":270,"postCount":271},"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":273,"name":274,"description":263,"image":42,"body":275,"postCount":276},"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":278,"name":87,"description":279,"image":42,"body":280,"postCount":281},"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":283,"name":284,"description":285,"image":42,"body":42,"postCount":286},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":288,"name":205,"description":263,"image":289,"body":290,"postCount":291},"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":293,"name":294,"description":285,"image":42,"body":42,"postCount":286},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":296,"name":297,"description":298,"image":299,"body":300,"postCount":301},"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.*",54,{"slug":303,"name":304,"description":305,"image":306,"body":307,"postCount":286},"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.",[309,316,322,327,332,337,341,345,349,354,358,363,367,372,377,381,385,389,393,398,402,406,410,415,419,423,427,431,436,441,445,449,453,458,462,466,470,474,478,482,486,490,494,498,502,506,510,514,519,523,527,531,535,539,543,547,551,555,559,563,567,571,575,579,583,587,591,595,598,602,605,608,611,614,617,620,623,626,629,632,635,638,640],{"slug":310,"name":311,"description":312,"image":313,"body":314,"postCount":315},"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":317,"name":318,"description":319,"image":42,"body":320,"postCount":321},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":323,"name":324,"description":325,"image":42,"body":42,"postCount":326},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",11,{"slug":328,"name":329,"description":330,"image":42,"body":42,"postCount":331},"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":333,"name":334,"description":335,"image":42,"body":42,"postCount":336},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":338,"name":339,"description":340,"image":42,"body":42,"postCount":326},"mycobacteria","Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":342,"name":343,"description":344,"image":42,"body":42,"postCount":321},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":346,"name":347,"description":348,"image":42,"body":42,"postCount":321},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":350,"name":351,"description":352,"image":42,"body":42,"postCount":353},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":355,"name":356,"description":357,"image":42,"body":42,"postCount":315},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":359,"name":360,"description":361,"image":42,"body":42,"postCount":362},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",21,{"slug":364,"name":365,"description":366,"image":42,"body":42,"postCount":315},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":368,"name":369,"description":370,"image":42,"body":42,"postCount":371},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":373,"name":374,"description":375,"image":42,"body":42,"postCount":376},"specimen-collection-transport","Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":378,"name":379,"description":380,"image":42,"body":42,"postCount":362},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",{"slug":382,"name":383,"description":42,"image":42,"body":384,"postCount":276},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":386,"name":387,"description":42,"image":42,"body":388,"postCount":371},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":81,"name":390,"description":391,"image":42,"body":392,"postCount":353},"Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":394,"name":395,"description":396,"image":42,"body":397,"postCount":276},"pcr-techniques","PCR Techniques","Information about various types of Polymerase Chain Reaction Techniques ","More detailed information about various types of Polymerase Chain Reaction Techniques ",{"slug":399,"name":400,"description":401,"image":42,"body":42,"postCount":276},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":403,"name":404,"description":405,"image":42,"body":42,"postCount":276},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":407,"name":408,"description":409,"image":42,"body":42,"postCount":276},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":411,"name":412,"description":413,"image":42,"body":42,"postCount":414},"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.",19,{"slug":416,"name":417,"description":418,"image":42,"body":42,"postCount":353},"biosafety-levels","Biosafety levels ","Articles related to Biosafety Levels",{"slug":420,"name":421,"description":422,"image":42,"body":42,"postCount":331},"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":424,"name":425,"description":426,"image":42,"body":42,"postCount":276},"pipette","Pipette","Posts related with Pipette. ",{"slug":428,"name":429,"description":430,"image":42,"body":42,"postCount":353},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":432,"name":433,"description":434,"image":42,"body":42,"postCount":435},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":437,"name":438,"description":439,"image":42,"body":42,"postCount":440},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":442,"name":443,"description":444,"image":42,"body":42,"postCount":331},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",{"slug":446,"name":447,"description":448,"image":42,"body":42,"postCount":336},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":450,"name":451,"description":452,"image":42,"body":42,"postCount":371},"microbial-curiosities","Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":454,"name":455,"description":456,"image":42,"body":42,"postCount":457},"bacterial-culture-media","Bacterial Culture Media","Posts related to Bacterial Culture Media. ",23,{"slug":459,"name":460,"description":461,"image":42,"body":42,"postCount":276},"fungal-culture-media","Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":463,"name":464,"description":465,"image":42,"body":42,"postCount":331},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":467,"name":468,"description":469,"image":42,"body":42,"postCount":371},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":471,"name":472,"description":473,"image":42,"body":42,"postCount":435},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":475,"name":476,"description":477,"image":42,"body":42,"postCount":440},"dimorphic-fungi","Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":479,"name":480,"description":481,"image":42,"body":42,"postCount":353},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":483,"name":484,"description":485,"image":42,"body":42,"postCount":331},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":487,"name":488,"description":489,"image":42,"body":42,"postCount":281},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":491,"name":492,"description":493,"image":42,"body":42,"postCount":353},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":495,"name":496,"description":42,"image":42,"body":42,"postCount":497},"haemophilus","Haemophilus",3,{"slug":499,"name":500,"description":501,"image":42,"body":42,"postCount":440},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":503,"name":504,"description":505,"image":42,"body":42,"postCount":321},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",{"slug":507,"name":508,"description":509,"image":42,"body":42,"postCount":315},"fungal-diagnostics","Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":511,"name":512,"description":513,"image":42,"body":42,"postCount":331},"laboratory-storage-and-preservation","Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":515,"name":516,"description":517,"image":42,"body":518,"postCount":276},"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":520,"name":521,"description":522,"image":42,"body":42,"postCount":281},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":524,"name":525,"description":526,"image":42,"body":42,"postCount":276},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":528,"name":529,"description":530,"image":42,"body":42,"postCount":353},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":532,"name":533,"description":534,"image":42,"body":42,"postCount":286},"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":536,"name":537,"description":538,"image":42,"body":42,"postCount":371},"bacterial-staining-technique","Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":540,"name":541,"description":542,"image":42,"body":42,"postCount":362},"enzyme-tests","Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":544,"name":545,"description":546,"image":42,"body":42,"postCount":326},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",{"slug":548,"name":549,"description":550,"image":42,"body":42,"postCount":331},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":552,"name":553,"description":554,"image":42,"body":42,"postCount":440},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":556,"name":557,"description":558,"image":42,"body":42,"postCount":336},"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":560,"name":561,"description":562,"image":42,"body":42,"postCount":497},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":564,"name":565,"description":566,"image":42,"body":42,"postCount":331},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":568,"name":569,"description":570,"image":42,"body":42,"postCount":353},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":572,"name":573,"description":574,"image":42,"body":42,"postCount":440},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":576,"name":577,"description":578,"image":42,"body":42,"postCount":331},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":580,"name":581,"description":582,"image":42,"body":42,"postCount":336},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":584,"name":585,"description":586,"image":42,"body":42,"postCount":276},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":588,"name":589,"description":590,"image":42,"body":42,"postCount":353},"genetic-code","Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":592,"name":593,"description":594,"image":42,"body":42,"postCount":353},"molecular-technique","Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":596,"name":597,"description":42,"image":42,"body":42,"postCount":286},"colorimetric-assay","Colorimetric Assay ",{"slug":599,"name":600,"description":601,"image":42,"body":42,"postCount":331},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":603,"name":604,"description":42,"image":42,"body":42,"postCount":497},"blood-and-immune-cells","Blood and Immune Cells",{"slug":606,"name":607,"description":42,"image":42,"body":42,"postCount":331},"host-pathogen-interaction","Host Pathogen Interaction",{"slug":609,"name":610,"description":42,"image":42,"body":42,"postCount":440},"blood-culture","Blood Culture",{"slug":612,"name":613,"description":42,"image":42,"body":42,"postCount":440},"environmental-microbiology","Environmental microbiology ",{"slug":615,"name":616,"description":42,"image":42,"body":42,"postCount":276},"copromicroscopic-technique","Copromicroscopic Technique",{"slug":618,"name":619,"description":42,"image":42,"body":42,"postCount":497},"quality-control","Quality Control",{"slug":621,"name":622,"description":42,"image":42,"body":42,"postCount":440},"dermatophytes","Dermatophytes",{"slug":624,"name":625,"description":42,"image":42,"body":42,"postCount":497},"viral-hemorrhagic-fevers","Viral Hemorrhagic Fevers",{"slug":627,"name":628,"description":42,"image":42,"body":42,"postCount":440},"h2s-production","H2S Production",{"slug":630,"name":631,"description":42,"image":42,"body":42,"postCount":435},"water-quality-testing","Water Quality Testing",{"slug":633,"name":634,"description":42,"image":42,"body":42,"postCount":331},"virology-basics","Virology basics",{"slug":636,"name":637,"description":42,"image":42,"body":42,"postCount":440},"typing-methods","Typing Methods",{"slug":116,"name":639,"description":42,"image":42,"body":42,"postCount":497},"Blotting Technique",{"slug":641,"name":642,"description":42,"image":42,"body":42,"postCount":440},"history-microbiology","History of Microbiology"]