[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$f00N1E74ILfzLmgaF_O4_Oqk3CCcrR9ouWZ2PxEdgMtQ":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":299,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":364},[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},"Abbreviations","abbreviations","\u002Fabbreviations\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},"Utilization Tests for Bacterial Identification","utilization-tests","\u002Futilization-tests\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":71,"related":73,"comments":295},"sterile-body-fluids-collection-transport-lab-diagnosis","Sterile Body Fluids: Collection and Transport (Pleural, Peritoneal, Pericardial, Synovial)","\u003Cp>How to collect and split pleural, ascitic, pericardial, and synovial fluid across the right containers, why some goes into a blood culture bottle, which anticoagulant not to use for joint fluid, and why these fluids are never refrigerated.\u003C\u002Fp>",null,"Acharya Tankeshwar","2026-08-14","2026-08-13",false,"bacteriology","Pleural, peritoneal (ascitic), pericardial, and synovial fluids come from body spaces that are normally sterile. That single fact drives everything: **because these sites have no resident flora, any organism the lab grows is a potential pathogen**, and there is no contamination allowance to fall back on. So the whole job is to aspirate cleanly, split the fluid into the right containers for the tests requested, and get it to the lab warm and fast. This page covers the shared logic for all four fluids. Cerebrospinal fluid and blood also follow the same principles but they are dealt on their own dedicated articles.\n\nThese fluids are **always collected by a trained clinician**, by percutaneous aspiration into a syringe (thoracentesis for pleural, paracentesis for peritoneal, pericardiocentesis for pericardial, arthrocentesis for synovial). The microbiology side does not collect them, but understanding the collection decides whether the specimen that arrives is usable.\n\n## The one principle: normally sterile means no contamination allowance\n\nFor urine or sputum, the lab expects some commensal flora and uses thresholds to separate infection from contamination. Sterile body fluids have no such buffer. A skin organism introduced by poor asepsis at the puncture looks exactly like a pathogen. So two things matter more here than almost anywhere else: **rigorous skin antisepsis before the needle goes** in, and **telling the lab the specimen came from a normally sterile site**, so it is handled and interpreted accordingly.\n\nSkin is disinfected with chlorhexidine or an iodine preparation before aspiration, the same care used for a [blood culture](https:\u002F\u002Fmicrobeonline.com\u002Fblood-culture-indications-timing-and-volume\u002F). The fluid is aspirated into a syringe, the needle is removed, and the fluid is transferred to the containers below. Never send a syringe with the needle still attached.\n\n## Splitting the fluid: which container for which test\n\n\u003Cfigure>\n\u003Cimg src=\"https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fsterile-fluid-specimen-split.png\" alt=\"One aspirate is split across containers by test. The microbiology share goes into blood culture bottles for enrichment plus a separate sterile aliquot for the Gram stain and direct plating, because the bottle alone cannot give a smear. An anticoagulant tube serves cell count and, for synovial fluid, crystals (liquid EDTA or heparin only). None of the containers is refrigerated, and because the site is normally sterile, any organism grown is significant.\" width=\"2720\" height=\"1920\" draggable=\"false\" contenteditable=\"false\">\u003Cfigcaption>Figure: One aspirate is split across containers by test. The microbiology share goes into blood culture bottles for enrichment plus a separate sterile aliquot for the Gram stain and direct plating, because the bottle alone cannot give a smear. An anticoagulant tube serves cell count and, for synovial fluid, crystals (liquid EDTA or heparin only). None of the containers is refrigerated, and because the site is normally sterile, any organism grown is significant.\u003C\u002Ffigcaption>\n\u003C\u002Ffigure>\n\nA body-fluid tap is often the only sample you will get, so it must be divided correctly the first time. Different tests need different containers, and putting the fluid in the wrong one can waste the whole tap.\n\n| Test requested | Container | Why |\n| --- | --- | --- |\n| Microbiology (Gram stain and culture) | Sterile leak-proof tube with no additive, or a blood culture bottle | Culture needs viable organisms and no interfering additive |\n| Cell count and differential | Anticoagulant tube (liquid EDTA or heparin) | Prevents clotting so cells can be counted |\n| Chemistry (protein, glucose, LDH, etc.) | Plain tube (no additive) | Additives interfere with chemistry |\n| Crystals (synovial fluid) | Liquid EDTA or sodium heparin, never oxalate or powdered EDTA | Wrong anticoagulant forms crystals that mimic disease |\n| Cytology (malignancy) | Anticoagulant tube, larger volume | More fluid recovers more cells |\n\nWhen volume is limited, prioritize by the clinical question. **If infection is the concern, microbiology comes first.** The order of filling also matters for the microbiology aliquot: like a blood culture, the specimen intended for culture should be handled so it stays as clean as possible.\n\n### Using a blood culture bottle, and why\n\nFor pleural, peritoneal, pericardial, and synovial fluid, inoculating a portion directly into blood culture bottles (aerobic and anaerobic) raises the yield, especially for low-count infections and for organisms that are hard to grow on plates. The bottle acts as an enrichment broth and, in automated systems, flags growth continuously.\n\nThe key habit: **if you put fluid into a blood culture bottle, also send a separate sterile aliquot (about 1 mL) for the [Gram stain](https:\u002F\u002Fmicrobeonline.com\u002Fgram-staining-principle-procedure-results\u002F) and for plating on solid media.** The bottle alone cannot give you a Gram stain result or isolated colonies for identification and susceptibility. Bottle for sensitivity, separate aliquot for the smear and the isolate.\n\n**A common volume guide:** put a few millilitres into each bottle (small volumes go into a pediatric bottle), and keep at least 1 mL aside in a sterile tube for direct examination.\n\n### Synovial fluid: the crystal trap\n\nJoint fluid carries an extra decision that the other fluids do not, because it is often tapped to distinguish septic arthritis from gout or pseudogout. Crystal analysis has a specific requirement:\n\n- Use liquid EDTA or sodium heparin for the cell count and crystal tube.\n- Do not use oxalate, lithium heparin, or powdered EDTA. These form their own crystals that look like the monosodium urate (gout) or calcium pyrophosphate (pseudogout) crystals you are trying to identify, producing false positives.\n\nAnd because a septic joint is an emergency, synovial fluid is a STAT specimen. White cells lyse over time, which falsely lowers the count and can make a septic joint look less inflamed than it is. Analyze it as soon as possible.\n\n## Transport: the rule that unites all four fluids\n\nLike CSF and blood cultures, and for the same reason, **sterile body fluids are not refrigerated.** [Refrigeration](https:\u002F\u002Fmicrobeonline.com\u002Flaboratory-refrigerator-temperature-and-storage\u002F) can kill fastidious organisms and, for synovial fluid, can precipitate crystals that create false results. Keep the specimen at room temperature and get it to the lab quickly. If a delay is unavoidable, hold at room temperature or at 35°C, never in the fridge. Alert the lab that a normally sterile specimen is on its way so it is prioritized.\n\nThe one exception to remember is that this contradicts the \"refrigerate if delayed\" rule used for urine and routine swabs. **Sterile fluids, like CSF and blood, sit in the do-not-refrigerate group.**\n\n## What the lab does with the specimen\n\nBecause these fluids come from normally sterile spaces, the laboratory reads them with the opposite assumption to a swab: there is no expected flora, so any organism recovered is potentially significant, and there is no contamination threshold to fall back on. The challenge is usually that organisms are few, so the processing is built around concentrating a low-count specimen.\n\n**Concentration first.** Unlike a swab, a fluid can be concentrated before examination. The specimen is centrifuged, and the smear and cultures are made from the sediment, which gathers the small number of organisms into a readable deposit. For very low-count fluids, a cytocentrifuge (cytospin) concentrates cells and organisms directly onto the slide, the same principle used for CSF.\n\n**Direct examination.** From the concentrated deposit:\n\n- A Gram stain is examined for bacteria, yeasts, and the pus-cell response.\n- Additional stains are added for the clinical question: a Ziehl-Neelsen or auramine stain when tuberculosis is suspected (for example a lymphocyte-rich pleural or peritoneal effusion), and a KOH or calcofluor-white preparation when a fungus is suspected.\n- For synovial fluid, a portion goes to polarized-light microscopy for crystals, which is a separate question from infection but is run on the same tap (recall the anticoagulant rule, so the anticoagulant itself does not create false crystals).\n\n**Culture, using both the bottle and a direct plate.** The workflow set up at collection now pays off:\n\n- The portion inoculated into **blood culture bottles** (aerobic and anaerobic) is loaded onto the automated system, where it acts as an enrichment broth and is monitored continuously for growth. This recovers low-count and fastidious organisms that a plate might miss.\n- The **separate sterile aliquot** is used for the direct Gram stain and for plating onto solid media (blood agar, chocolate agar, MacConkey), which provides the isolated colonies the bottle cannot.\n- Media are chosen for the expected pathogens, with anaerobic and fungal or mycobacterial media added when the clinical picture warrants.\n\n**Incubation.** Bacterial plates and bottles are incubated at 35 to 37 degrees C, with chocolate agar in 5% CO2, and read over 24 to 48 hours and beyond. Fungal and mycobacterial cultures are held for weeks.\n\n**Reading and interpretation.**\n\n- Because the site is normally sterile, a single significant organism is meaningful, and there is no colony-count threshold as there is for urine. Growth is not dismissed as scant.\n- Growth is still read against the direct smear and the cell count: an organism seen on the Gram stain of the sediment and then grown is highly convincing, while a single colony from the bottle only, with a bland smear and low cell count, may reflect a skin contaminant introduced at the tap, which is exactly why bedside asepsis matters so much.\n- The cell count and differential support the read: a neutrophil-rich fluid points to acute bacterial infection, while a lymphocyte-rich fluid raises tuberculosis or a chronic or malignant process.\n\n## **Identification and antimicrobial susceptibility testing**\n\nThe organisms commonly isolated, and the approach to each:\n\n- ***Staphylococcus aureus***: gram-positive cocci in clusters, catalase and coagulase positive; a leading cause of septic arthritis and of pleural and peritoneal infection. See the *Staphylococcus aureus* page.\n- ***Streptococcus pneumoniae* and other streptococci**: gram-positive cocci in pairs or chains; causes of empyema and primary peritonitis. See the relevant spoke.\n- **Enterobacterales (*Escherichia coli*, *Klebsiella*)**: gram-negative bacilli, common in secondary peritonitis and in spontaneous bacterial peritonitis. See each spoke.\n- ***Neisseria gonorrhoeae***: gram-negative diplococci; a cause of septic arthritis in young adults, needing appropriate media. See the *Neisseria gonorrhoeae* page.\n- ***Mycobacterium tuberculosis***: acid-fast; suspected in a lymphocyte-rich effusion, needing mycobacterial stains and culture and often molecular testing. See the tuberculosis page.\n\n## How to Remember\n\n**Sterile site, no second chances.** These spaces have no normal flora, so any growth counts and any contaminant misleads. Clean the skin like a blood culture, and tell the lab it is a sterile-site specimen.\n\n**Split the tap right the first time.** One aspirate, several tests. Sterile tube or bottle for micro, anticoagulant tube for cell count, plain tube for chemistry. Get it wrong and the tap is wasted.\n\n**Bottle plus aliquot.** Blood culture bottle raises the yield, but always keep a separate sterile aliquot for the Gram stain and the plate. Bottle for growth, aliquot for the smear and the isolate.\n\n**Wrong anticoagulant makes fake crystals.** For joint fluid, use liquid EDTA or sodium heparin. Oxalate, lithium heparin, and powdered EDTA form crystals that mimic gout and pseudogout. The anticoagulant can invent the disease.\n\n**Sterile fluids join the do-not-refrigerate club.** CSF, blood, and these four fluids all stay warm. Only urine and routine swabs get the fridge.\n\n## Key exam facts in one table\n\n| Point | Fact |\n| --- | --- |\n| Fluids covered | Pleural, peritoneal (ascitic), pericardial, synovial |\n| Collected by | Trained clinician, percutaneous aspiration |\n| Skin prep | Chlorhexidine or iodine, blood-culture-level asepsis |\n| Why it matters | Normally sterile site: any organism is significant, no contamination allowance |\n| Microbiology container | Sterile no-additive tube or blood culture bottle |\n| Cell count container | Anticoagulant (liquid EDTA or heparin) |\n| Chemistry container | Plain tube |\n| Crystal analysis anticoagulant | Liquid EDTA or sodium heparin only |\n| Crystal analysis avoid | Oxalate, lithium heparin, powdered EDTA (form false crystals) |\n| Blood culture bottle | Raises yield; always keep a separate aliquot for Gram stain and plate |\n| Never send | Syringe with needle attached |\n| Transport | Room temperature, fast; do NOT refrigerate |\n| Synovial fluid | STAT (cells lyse, count falls; septic joint is an emergency) |\n| Alert the lab | Yes, that a normally sterile specimen is coming |\n\n## Where Students Get Confused\n\n**\"These fluids are sterile, so why be so careful about skin cleaning?\"** Precisely because they are sterile. There is no normal flora to compare against, so a single skin organism introduced at the puncture looks identical to a true pathogen. Blood-culture-level asepsis is what keeps the result trustworthy.\n\n**\"Why put fluid in a blood culture bottle instead of just a sterile tube?\"** The bottle is an enrichment broth and, in automated systems, watches for growth continuously, so it recovers low-count and fastidious organisms better. But it cannot give a Gram stain or isolated colonies, so you always keep a separate aliquot for the smear and the plate.\n\n**\"Any anticoagulant is fine for the cell count, right?\"** Not for synovial fluid. Oxalate, lithium heparin, and powdered EDTA form crystals that look like gout or pseudogout crystals, causing false positives. Use liquid EDTA or sodium heparin for joint fluid.\n\n**\"Can I refrigerate a body fluid if the lab is closed?\"** No. Like CSF and blood cultures, these fluids are kept at room temperature. Cold harms fastidious organisms and can precipitate crystals in joint fluid. This is the opposite of the urine rule.\n\n**\"The tap gave only a little fluid, which test gets it?\"** Prioritize by the clinical question. If infection is suspected, microbiology comes first. Tell the lab the volume is limited so it can decide the order of testing.\n\n### References and further reading\n\n1. Tille PM. *Bailey & Scott's Diagnostic Microbiology.* 15th ed. St. Louis: Elsevier; 2022.\n2. Leber AL, editor. *Clinical Microbiology Procedures Handbook.* 4th ed. Washington, DC: ASM Press; 2016. DOI: 10.1128\u002F9781683670438.CMPH\n3. CLSI. *Body Fluid Analysis for Cellular Composition; Approved Guideline.* CLSI document H56. Wayne, PA: Clinical and Laboratory Standards Institute.",[50,53,56,59,62,65,68],{"question":51,"answer":52},"\u003Cp>Why is skin antisepsis so important for sterile body fluids?\u003C\u002Fp>","\u003Cp>Because these sites are normally sterile, there is no commensal flora to compare against, so a single organism introduced at the puncture looks exactly like a true pathogen. Careful chlorhexidine or iodine antisepsis, at the level used for a blood culture, keeps the result reliable.\u003C\u002Fp>",{"question":54,"answer":55},"\u003Cp>How should a body-fluid tap be divided?\u003C\u002Fp>","\u003Cp>Into separate containers by test: a sterile no-additive tube or blood culture bottle for microbiology, an anticoagulant tube (liquid EDTA or heparin) for cell count, and a plain tube for chemistry. When volume is limited, prioritize the test that answers the clinical question, usually microbiology if infection is suspected.\u003C\u002Fp>",{"question":57,"answer":58},"\u003Cp>Why inoculate body fluid into a blood culture bottle?\u003C\u002Fp>","\u003Cp>The bottle acts as an enrichment broth and, in automated systems, detects growth continuously, improving recovery of low-count and fastidious organisms. Always send a separate sterile aliquot as well, because the bottle cannot provide a Gram stain or isolated colonies for identification.\u003C\u002Fp>",{"question":60,"answer":61},"\u003Cp>Which anticoagulant should be used for synovial fluid crystal analysis?\u003C\u002Fp>","\u003Cp>Liquid EDTA or sodium heparin. Avoid oxalate, lithium heparin, and powdered EDTA, because they form crystals that resemble gout and pseudogout crystals and cause false-positive results.\u003C\u002Fp>",{"question":63,"answer":64},"\u003Cp>Should sterile body fluids be refrigerated if there is a delay?\u003C\u002Fp>","\u003Cp>No. Like CSF and blood cultures, they are kept at room temperature. Refrigeration can kill fastidious organisms and, in joint fluid, precipitate crystals. This is the opposite of the rule for urine.\u003C\u002Fp>",{"question":66,"answer":67},"\u003Cp>Why is synovial fluid treated as urgent?\u003C\u002Fp>","\u003Cp>Because a septic joint is an emergency and because white cells lyse over time, which falsely lowers the cell count and can make a septic joint appear less inflamed than it is. Analyze it as soon as possible.\u003C\u002Fp>",{"question":69,"answer":70},"\u003Cp>Why must the lab be told the specimen is from a sterile site?\u003C\u002Fp>","\u003Cp>So it is handled as a specimen where any growth is significant, processed promptly, and interpreted without a contamination allowance. It also ensures the specimen is prioritized appropriately.\u003C\u002Fp>",[72],"specimen-collection-transport",[74,106,127,151,181,209,237,267],{"slug":75,"title":76,"description":77,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":78,"lastUpdatedDate":79,"draft":46,"category":47,"image":42,"faq":80,"tags":105},"blood-culture-indications-timing-and-volume","Blood Culture: Indications, Timing, and Volume","\u003Cp>When to draw blood cultures and why, why volume matters more than timing, how many sets to collect, how to draw from a peripheral vein versus a central line, and how paired cultures diagnose a line infection.\u003C\u002Fp>","2018-09-25","2026-08-12",[81,84,87,90,93,96,99,102],{"question":82,"answer":83},"\u003Cp>Why does blood volume matter more than the timing of collection?\u003C\u002Fp>","\u003Cp>Most adult bacteremias carry very few organisms per millilitre of blood, so the more blood cultured, the higher the chance of catching one. Studies show total volume drives yield far more than the exact minute of collection.\u003C\u002Fp>",{"question":85,"answer":86},"\u003Cp>How many blood culture sets should be collected, and why not just one?\u003C\u002Fp>","\u003Cp>At least two, preferably three, each from a separate venipuncture. A single set gives too little volume and cannot distinguish a skin contaminant from a true pathogen. A contaminant usually appears in only one set, while a real pathogen appears in several.\u003C\u002Fp>",{"question":88,"answer":89},"\u003Cp>How much blood goes into each bottle for an adult?\u003C\u002Fp>","\u003Cp>About 10 mL per bottle, with two bottles (aerobic and anaerobic) per set, so roughly 20 mL per set. Under-filling is a common reason a true infection is missed.\u003C\u002Fp>",{"question":91,"answer":92},"\u003Cp>Should blood cultures be drawn from a peripheral vein or an existing line?\u003C\u002Fp>","\u003Cp>A fresh peripheral venipuncture is preferred, because drawing through a catheter picks up hub organisms and raises the false-positive rate. Draw from a line only when peripheral access fails, or deliberately as a paired sample when the line itself is the suspected source of infection.\u003C\u002Fp>",{"question":94,"answer":95},"\u003Cp>What is differential time to positivity?\u003C\u002Fp>","\u003Cp>When a catheter set and a peripheral set are drawn at the same time, the catheter bottle turns positive earlier if the line is colonized, because it carries a heavier bacterial load. A catheter set flagging positive 2 hours or more before the peripheral set supports a catheter-related bloodstream infection.\u003C\u002Fp>",{"question":97,"answer":98},"\u003Cp>Which skin antiseptic should be used before drawing blood cultures?\u003C\u002Fp>","\u003Cp>Chlorhexidine-alcohol is preferred because it gives lower contamination rates and does not need to be wiped off. Tincture of iodine is an acceptable alternative. Povidone-iodine works but must be left to dry in contact for at least 2 minutes.\u003C\u002Fp>",{"question":100,"answer":101},"\u003Cp>Can blood culture bottles be refrigerated if there is a delay?\u003C\u002Fp>","\u003Cp>No. Keep them at room temperature and get them to the incubator, for a maximum of about 4 hours. Refrigeration harms the organisms you are trying to grow.\u003C\u002Fp>",{"question":103,"answer":104},"\u003Cp>How much blood is safe to take from an infant?\u003C\u002Fp>","\u003Cp>The volume is based on the child's weight, and no more than about 4 to 4.5% of total blood volume should be taken. Pediatric bottles are designed to keep the correct blood-to-broth ratio at these smaller volumes.\u003C\u002Fp>",[72],{"slug":107,"title":108,"description":109,"seoTitle":110,"seoDescription":111,"author":43,"createdDate":112,"lastUpdatedDate":113,"draft":46,"category":114,"image":42,"faq":115,"tags":125},"gram-staining-principle-procedure-results","Gram Staining: Step-by-Step Procedure, Results & Interpretation Guide","Master gram staining: step-by-step procedure, results interpretation, clinical significance of each gram stain pattern, organism-specific appearances, quality control, and troubleshooting.","Gram Stain: Procedure, Results, Troubleshooting, and Interpretation","Perform Gram staining step by step, interpret common cellular patterns, troubleshoot weak or mixed results, and connect findings with organism identity.","2015-02-02","2026-08-02","staining-techniques",[116,119,122],{"question":117,"answer":118},"What does it mean if neutrophil nuclei appear blue instead of red on a Gram stain?","Neutrophil nuclei staining blue\u002Fpurple instead of red\u002Fpink indicates under-decolourisation — the decolorising agent (alcohol or acetone-alcohol) was not applied for long enough, or was too dilute. In this situation, gram-negative organisms may also retain the crystal violet and appear falsely gram-positive. The entire slide must be repeated with correct decolourisation technique: drop-by-drop application until the effluent runs clear, approximately 10-15 seconds.",{"question":120,"answer":121},"What is the clinical significance of gram-negative intracellular diplococci in a urethral smear?","Gram-negative intracellular diplococci (GNID) in a urethral or cervical smear is presumptive evidence of Neisseria gonorrhoeae infection and is sufficient justification to start treatment immediately, before culture confirmation. The sensitivity of this finding in symptomatic males is approximately 90-95%; sensitivity is lower in females and asymptomatic individuals. In a CSF specimen, gram-negative diplococci — intracellular within neutrophils — indicate probable Neisseria meningitidis meningitis, a medical emergency requiring immediate ceftriaxone.",{"question":123,"answer":124},"Why do gram-positive bacteria sometimes stain gram-negative?","Gram-positive bacteria can appear gram-negative due to: over-decolourisation (most common — decoloriser applied too long or too vigorously); cell wall damage from antibiotic therapy (beta-lactams damage peptidoglycan, reducing crystal violet retention); use of old or degraded iodine solution (yellow rather than dark brown); old culture age (aging cells lose cell wall integrity); or excessive heat fixation distorting the smear. When gram-positive control organisms also stain incorrectly, the reagents should be investigated first.",[126],"bacterial-staining-technique",{"slug":128,"title":129,"description":130,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":131,"lastUpdatedDate":79,"draft":46,"category":132,"image":42,"faq":133,"tags":149},"laboratory-refrigerator-temperature-and-storage","Laboratory Refrigerator: Temperature, What to Store at Each, and Storage Rules","Laboratory refrigerator temperatures explained, which reagents, sera, vaccines, and blood products belong at 2-8 degrees C, why freezing destroys some of them, and the storage rules that keep samples usable. A practical guide for lab science students.","2026-07-28","lab-equipment",[134,137,140,143,146],{"question":135,"answer":136},"What temperature is a laboratory refrigerator set to?","A laboratory refrigerator is kept at 2–8°C, with about 4°C as the usual set point. This range slows chemical reactions, enzyme activity, and microbial growth while staying above freezing, which protects reagents, sera, vaccines, and blood products that ice crystals would damage.",{"question":138,"answer":139},"Why are some reagents and vaccines refrigerated instead of frozen?","Freezing forms ice crystals that denature proteins and rupture cells, which destroys many control sera, antibodies, and vaccines. For these items, 2–8°C preserves activity while freezing would ruin them, so colder is not automatically better.",{"question":141,"answer":142},"Why are platelets not stored in the refrigerator?","Platelets are stored at 20–24°C (room temperature) with continuous gentle agitation. Refrigeration damages platelet function and stillness causes them to clump, so unlike red cells and plasma, platelets are never refrigerated.",{"question":144,"answer":145},"Why should nothing sensitive be stored in the refrigerator door?","The door is the warmest and most temperature-variable part of the refrigerator, because it warms every time the fridge is opened. Sensitive items such as controls, sera, vaccines, and blood should be kept on the internal shelves where the temperature is stable.",{"question":147,"answer":148},"What is the difference between a laboratory refrigerator and a blood bank refrigerator?","A blood bank refrigerator is a specialized laboratory refrigerator held at 2–6°C with a tighter temperature tolerance, a continuous temperature log, and an audible alarm. The stricter monitoring exists because a temperature error can make blood unsafe to transfuse.",[150],"laboratory-storage-and-preservation",{"slug":152,"title":153,"description":154,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":155,"lastUpdatedDate":156,"draft":46,"category":157,"image":42,"faq":158,"tags":180},"sample-collections-for-laboratory-diagnosis-of-fungal-infections","Sample Collection for Fungal Infections: Which Specimen, How to Collect and Transport","\u003Cp>Which specimen to collect for a suspected fungal infection by site, how to collect skin, nail, hair, blood, CSF, respiratory, urine, and tissue correctly, and the transport rule.\u003C\u002Fp>","2021-04-03","2026-08-17","mycology",[159,162,165,168,171,174,177],{"question":160,"answer":161},"\u003Cp>Why is a skin scraping better than a swab for a suspected fungal infection?\u003C\u002Fp>","\u003Cp>The fungus lives in the keratin at the advancing edge of the lesion, not loose on the surface. A swab collects surface debris and often misses the fungus, while scraping the growing margin with a slide edge or scalpel collects the living organism. Swabs give more false-negative results for dermatophyte infections.\u003C\u002Fp>",{"question":163,"answer":164},"\u003Cp>Should fungal specimens be refrigerated if there is a delay?\u003C\u002Fp>","\u003Cp>Almost never. Skin, nail, hair, CSF, blood, and tissue are kept at room temperature. Only urine is refrigerated (at 4°C) if processing is delayed beyond 2 hours. The rule is: warm for nearly all fungal specimens, refrigerate only urine.\u003C\u002Fp>",{"question":166,"answer":167},"\u003Cp>How should nail specimens be collected?\u003C\u002Fp>","\u003Cp>From beneath the nail plate, sampling the softened subungual material from the nail bed, because that is where the fungus grows. If that is not possible, scrape away the surface of the nail and collect shavings from the deeper portions. A surface clipping alone is a poor specimen.\u003C\u002Fp>",{"question":169,"answer":170},"\u003Cp>Why must hairs be plucked rather than cut?\u003C\u002Fp>","\u003Cp>The infection is at the hair root and the base of the shaft. Cutting the hair leaves the diagnostic part on the scalp. Hairs are plucked with forceps so the root is included, and a Wood lamp can help identify which hairs to sample.\u003C\u002Fp>",{"question":172,"answer":173},"\u003Cp>Where on a ringworm lesion should the scraping be taken?\u003C\u002Fp>","\u003Cp>From the raised, red, advancing margin. The center of the lesion is often healing and holds little live fungus, while the active edge is where the fungus is growing.\u003C\u002Fp>",{"question":175,"answer":176},"\u003Cp>Can tissue for fungal culture be placed in formalin?\u003C\u002Fp>","\u003Cp>No. Formalin kills the fungus and makes culture impossible. Send fresh tissue kept moist in sterile saline for culture, and a separate portion in formalin only if histopathology is also requested.\u003C\u002Fp>",{"question":178,"answer":179},"\u003Cp>Why is a 24-hour urine sample not accepted for fungal culture?\u003C\u002Fp>","\u003Cp>Pooling urine over 24 hours lets contaminating bacteria overgrow, which obscures the fungus. A fresh first early-morning sample is preferred, refrigerated if there is a delay.\u003C\u002Fp>",[72],{"slug":182,"title":183,"description":184,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":185,"lastUpdatedDate":79,"draft":46,"category":47,"image":42,"faq":186,"tags":208},"key-points-laboratory-diagnosis-lower-respiratory-tract-infections","Sputum Sample: Collection, Transport, Staining, and Culture","\u003Cp>How to collect a good sputum sample, why the first morning specimen matters, the ideal-to-compromise order when a patient cannot expectorate, the cell criteria that decide accept or reject, and correct transport timing.\u003C\u002Fp>","2013-09-04",[187,190,193,196,199,202,205],{"question":188,"answer":189},"\u003Cp>Why is the first morning sputum sample preferred?\u003C\u002Fp>","\u003Cp>Secretions pool in the lower airways overnight, so the first deep cough of the day gives the most concentrated lower-airway material. For tuberculosis this raises the bacillary yield.\u003C\u002Fp>",{"question":191,"answer":192},"\u003Cp>How does the laboratory decide a sputum sample is really sputum and not saliva?\u003C\u002Fp>","\u003Cp>It screens a Gram-stained smear under low power. A good expectorated sample has more than 25 neutrophils and fewer than 10 squamous epithelial cells per low power field. Many squamous cells indicate saliva, and the sample is rejected. This screen applies to expectorated sputum only.\u003C\u002Fp>",{"question":194,"answer":195},"\u003Cp>Why is induced sputum sometimes rejected even though it is a valid sample?\u003C\u002Fp>","\u003Cp>Induced sputum is watery and cell-poor, so it fails the squamous-cell screen that is designed for expectorated samples. If it is labeled as induced, the lab bypasses that screen and processes it. Unlabeled, it can be wrongly rejected.\u003C\u002Fp>",{"question":197,"answer":198},"\u003Cp>What sample is used when a patient cannot cough up sputum?\u003C\u002Fp>","\u003Cp>Step up the invasiveness only as far as needed: induced sputum first, then endotracheal or tracheostomy aspirate in intubated patients, then bronchoscopy with BAL for immunocompromised or non-resolving cases. In young children, gastric aspirate (for TB) or bronchoscopy is often used because children swallow their sputum.\u003C\u002Fp>",{"question":200,"answer":201},"\u003Cp>How quickly must sputum reach the laboratory, and can it be refrigerated?\u003C\u002Fp>","\u003Cp>Process within 1 to 2 hours at room temperature. If delayed, refrigerate at 2 to 8 degrees C for up to 24 hours, except when a fastidious organism such as pneumococcus or \u003Cem>Haemophilus influenzae\u003C\u002Fem> is suspected, since cold lowers their recovery.\u003C\u002Fp>",{"question":203,"answer":204},"\u003Cp>Why might a hospitalized patient's gram-negative growth be ignored?\u003C\u002Fp>","\u003Cp>Intubated and hospitalized patients are colonized by gram-negative and nosocomial flora within days. A few colonies without matching clinical signs usually mean colonization, not infection, so identification and susceptibility testing would not change treatment.\u003C\u002Fp>",{"question":206,"answer":207},"\u003Cp>What concentration of saline is used for sputum induction?\u003C\u002Fp>","\u003Cp>Nebulized hypertonic saline, 3% to 7% NaCl. Normal saline (0.9%) is too dilute to irritate the airway and trigger a productive cough.\u003C\u002Fp>",[72],{"slug":210,"title":211,"description":212,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":213,"lastUpdatedDate":45,"draft":46,"category":47,"image":42,"faq":214,"tags":236},"collection-storage-and-transport-of-fecal-specimens-stool-for-microbiological-investigations","Stool Sample: Collection and Transport","\u003Cp>How to collect a stool sample correctly, how many samples and when, the rectal-swab compromise and when it is used, which transport medium or preservative to choose for bacteria versus parasites, and the storage rules that differ between them.\u003C\u002Fp>","2013-02-03",[215,218,221,224,227,230,233],{"question":216,"answer":217},"\u003Cp>How many stool samples are needed to look for parasites?\u003C\u002Fp>","\u003Cp>Three samples collected on separate days, because parasites are shed intermittently and a single stool can be falsely negative. For bacterial culture, one fresh sample in the acute phase is usually enough.\u003C\u002Fp>",{"question":219,"answer":220},"\u003Cp>When is a rectal swab acceptable instead of passed stool?\u003C\u002Fp>","\u003Cp>When passed stool cannot be obtained, for example in neonates or severely debilitated patients. The swab must be inserted past the anal sphincter and be visibly stained with feces, then placed in Cary-Blair. It is suitable for bacterial culture but not for parasite examination or C. difficile toxin testing.\u003C\u002Fp>",{"question":222,"answer":223},"\u003Cp>Which transport medium should a stool sample go into?\u003C\u002Fp>","\u003Cp>For enteric bacteria, Cary-Blair is the medium of choice. For parasites, use a preservative instead: formalin for concentration methods and PVA or a single-vial fixative for permanent stains. Bacteria and parasites need different chemistry.\u003C\u002Fp>",{"question":225,"answer":226},"\u003Cp>Can a delayed stool sample always be refrigerated?\u003C\u002Fp>","\u003Cp>Only for bacterial culture and for cysts and ova. An unpreserved liquid stool intended for trophozoite examination must not be refrigerated, since cold kills the motile trophozoites. Examine it fresh within about 30 minutes or fix it immediately.\u003C\u002Fp>",{"question":228,"answer":229},"\u003Cp>How much stool should be collected?\u003C\u002Fp>","\u003Cp>About 5 mL if the stool is liquid, or 2 grams (roughly two bean-sized portions) if formed. Sample any blood or mucus specifically, since pathogens concentrate there in dysentery.\u003C\u002Fp>",{"question":231,"answer":232},"\u003Cp>Why should stool not be collected from a bedpan?\u003C\u002Fp>","\u003Cp>Bedpans may contain residual disinfectant that kills pathogens, and the sample can be contaminated with urine. Collect directly into a clean, dry, wide-mouth container.\u003C\u002Fp>",{"question":234,"answer":235},"\u003Cp>When are stool cultures positive in typhoid fever?\u003C\u002Fp>","\u003Cp>Mainly from the second to third week of illness onward. In the first week, blood culture is the higher-yield test.\u003C\u002Fp>",[72],{"slug":238,"title":239,"description":240,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":79,"lastUpdatedDate":44,"draft":46,"category":47,"image":42,"faq":241,"tags":266},"specimen-collection-diagnosis-urinary-tract-infection","Urine Culture: Sample Collection, Transport and Lab Diagnosis ","\u003Cp>The organisms that cause UTI, how to collect and culture urine correctly, and how to read colony counts to separate real infection from contamination.\u003C\u002Fp>",[242,245,248,251,254,257,260,263],{"question":243,"answer":244},"\u003Cp>When should urine be sent for culture, and when should it not?\u003C\u002Fp>","\u003Cp>Send it only when there is real clinical suspicion of UTI: suspected pyelonephritis (loin pain and fever), UTI in men, recurrent UTI, pregnancy, or failed empiric treatment. Culturing every patient risks detecting asymptomatic bacteriuria, which usually does not need treatment.\u003C\u002Fp>",{"question":246,"answer":247},"\u003Cp>Which collection method gives the least contaminated sample?\u003C\u002Fp>","\u003Cp>Suprapubic aspiration, because the needle enters the bladder directly and bypasses the urethra. It is reserved for infants, young children, or cases where other methods fail. For routine adults, the clean-catch midstream sample is the practical standard despite its higher contamination risk.\u003C\u002Fp>",{"question":249,"answer":250},"\u003Cp>Why can urine never be cultured from a catheter drainage bag?\u003C\u002Fp>","\u003Cp>Bacteria multiply in the bag, so the count no longer reflects what is in the bladder. For a catheterized patient, clamp the tubing above the port, disinfect the port, and aspirate fresh urine through it.\u003C\u002Fp>",{"question":252,"answer":253},"\u003Cp>What does the calibrated loop actually do, and why does the angle matter so much?\u003C\u002Fp>","\u003Cp>It delivers a fixed, reproducible volume of urine (commonly 1 microlitre) so that counting colonies gives an estimate of CFU per mL. The result depends entirely on picking up that exact volume, so the loop must be held vertical and dipped only a few millimetres. A tilted or over-dipped loop delivers the wrong volume and invalidates the count.\u003C\u002Fp>",{"question":255,"answer":256},"\u003Cp>Why is \u003Cem>Staphylococcus aureus\u003C\u002Fem> in the urine treated differently from other organisms?\u003C\u002Fp>","\u003Cp>\u003Cem>S. aureus\u003C\u002Fem> usually reaches the kidney through the bloodstream rather than by ascending the urethra. So\u003Cem> S. aureus\u003C\u002Fem> in urine raises the question of a bloodstream infection, and any count from a suprapubic or catheter specimen can be significant rather than dismissed as a low count.\u003C\u002Fp>",{"question":258,"answer":259},"\u003Cp>Is \u003Cem>Staphylococcus saprophyticus\u003C\u002Fem> a contaminant like other coagulase-negative staphylococci?\u003C\u002Fp>","\u003Cp>No. Most coagulase-negative staphylococci in urine are skin contaminants, but \u003Cem>S. saprophyticus\u003C\u002Fem> is a genuine uropathogen in young women and should not be dismissed in a symptomatic patient.\u003C\u002Fp>",{"question":261,"answer":262},"\u003Cp>How quickly must urine reach the laboratory?\u003C\u002Fp>","\u003Cp>Within 1 to 2 hours at room temperature. If delayed, refrigerate at 2 to 8 degrees C for up to 24 hours, or use a boric acid preservative tube. Urine left warm overgrows and can turn a contaminant or a low count into a falsely significant result.\u003C\u002Fp>",{"question":264,"answer":265},"\u003Cp>Why is nitrofurantoin a poor choice for pyelonephritis?\u003C\u002Fp>","\u003Cp>It reaches good concentrations in the bladder urine but poor levels in the kidney tissue (renal parenchyma). That makes it effective for lower UTI (cystitis) but inadequate for a kidney infection. Fosfomycin is avoided in pyelonephritis for the same reason.\u003C\u002Fp>",[72],{"slug":268,"title":269,"description":270,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":271,"lastUpdatedDate":44,"draft":46,"category":47,"image":42,"faq":272,"tags":294},"tissue-biopsy-specimen-collection-transport","Tissue and Biopsy Specimens: Collection, Transport, and Processing","\u003Cp>Why tissue is the reference-standard specimen for deep infection, why the microbiology portion must be split off before formalin or decalcification, when to mince instead of grind, and how one small biopsy is divided across bacterial, AFB, fungal, and histology testing.\u003C\u002Fp>","2026-08-15",[273,276,279,282,285,288,291],{"question":274,"answer":275},"\u003Cp>Why is tissue considered the best specimen for deep infections?\u003C\u002Fp>","\u003Cp>A biopsy samples the organisms actually invading the tissue rather than the flora on the surface, so it is the reference-standard specimen for deep, chronic, and serious infections such as osteomyelitis and deep abscesses. This is why the pus, wound, and sterile-fluid pages point to tissue when it can be obtained.\u003C\u002Fp>",{"question":277,"answer":278},"\u003Cp>Why must tissue for culture never be placed in formalin?\u003C\u002Fp>","\u003Cp>Formalin kills all organisms, making culture impossible. The microbiology portion must be separated into a sterile container before any part of the specimen touches formalin. Once tissue is fixed, it can be used only for histopathology.\u003C\u002Fp>",{"question":280,"answer":281},"\u003Cp>How is a single small biopsy divided across several tests?\u003C\u002Fp>","\u003Cp>The fresh microbiology portions (bacterial, mycobacterial, and fungal) are taken first, kept moist in a sterile container, and only then is the remaining piece placed in formalin for histopathology. When volume is limited, the clinician and laboratory prioritize together based on the most likely diagnosis.\u003C\u002Fp>",{"question":283,"answer":284},"\u003Cp>Why is tissue minced instead of ground when mucormycosis is suspected?\u003C\u002Fp>","\u003Cp>The hyphae of \u003Cem>Mucorales\u003C\u002Fem> molds are broad, non-septate, and fragile. Grinding shatters them and produces a false-negative culture even when the fungus is visible on histology. Mincing the tissue preserves viable hyphae, so suspected mucormycosis must be flagged for the laboratory.\u003C\u002Fp>",{"question":286,"answer":287},"\u003Cp>Why can bone sent for histology not also be cultured?\u003C\u002Fp>","\u003Cp>Bone for histopathology is decalcified in acid, which kills organisms just as formalin does. The culture portion of a bone specimen must be split off fresh before any fixation or decalcification, or nothing viable remains to grow.\u003C\u002Fp>",{"question":289,"answer":290},"\u003Cp>How should tissue be kept during transport?\u003C\u002Fp>","\u003Cp>In a sterile, leak-proof container with only a few drops of sterile saline to keep it moist, not submerged. Deliver it promptly, use an anaerobic transport system if anaerobes are suspected, and flag any suspected TB, fungal, or \u003Cem>Mucorales\u003C\u002Fem> infection on the request.\u003C\u002Fp>",{"question":292,"answer":293},"\u003Cp>Should tissue specimens be refrigerated if delayed?\u003C\u002Fp>","\u003Cp>A short delay at refrigeration temperature is acceptable for routine bacterial culture, but not when fastidious organisms are suspected. Keep those at room temperature and transport quickly.\u003C\u002Fp>",[72],{"enabled":296,"threads":297,"total":298},true,[],0,[300,306,313,320,326,331,337,342,348,351,358],{"slug":301,"name":43,"description":302,"image":303,"body":304,"postCount":305},"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.*",468,{"slug":307,"name":308,"description":309,"image":310,"body":311,"postCount":312},"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.",78,{"slug":314,"name":315,"description":316,"image":317,"body":318,"postCount":319},"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":321,"name":322,"description":316,"image":323,"body":324,"postCount":325},"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":327,"name":328,"description":316,"image":42,"body":329,"postCount":330},"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":332,"name":333,"description":334,"image":42,"body":335,"postCount":336},"aastha-shrestha","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":338,"name":339,"description":340,"image":42,"body":42,"postCount":341},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":343,"name":344,"description":316,"image":345,"body":346,"postCount":347},"srijana-khanal","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.",17,{"slug":349,"name":350,"description":340,"image":42,"body":42,"postCount":341},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":352,"name":353,"description":354,"image":355,"body":356,"postCount":357},"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":359,"name":360,"description":361,"image":362,"body":363,"postCount":341},"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.",[365,372,378,383,388,393,397,401,405,410,414,419,423,428,432,436,440,444,449,454,458,462,466,471,475,479,483,487,492,497,501,505,509,513,517,521,525,529,533,537,541,545,549,553,557,561,565,568,573,577,581,585,589,592,596,600,604,608,612,616,620,624,628,632,636,640,644,648,651,655],{"slug":366,"name":367,"description":368,"image":369,"body":370,"postCount":371},"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":373,"name":374,"description":375,"image":42,"body":376,"postCount":377},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":379,"name":380,"description":381,"image":42,"body":42,"postCount":382},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",11,{"slug":384,"name":385,"description":386,"image":42,"body":42,"postCount":387},"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":389,"name":390,"description":391,"image":42,"body":42,"postCount":392},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":394,"name":395,"description":396,"image":42,"body":42,"postCount":382},"mycobacteria","Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":398,"name":399,"description":400,"image":42,"body":42,"postCount":382},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":402,"name":403,"description":404,"image":42,"body":42,"postCount":377},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":406,"name":407,"description":408,"image":42,"body":42,"postCount":409},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":411,"name":412,"description":413,"image":42,"body":42,"postCount":371},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":415,"name":416,"description":417,"image":42,"body":42,"postCount":418},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",21,{"slug":420,"name":421,"description":422,"image":42,"body":42,"postCount":392},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":424,"name":425,"description":426,"image":42,"body":42,"postCount":427},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":72,"name":429,"description":430,"image":42,"body":42,"postCount":431},"Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":433,"name":434,"description":435,"image":42,"body":42,"postCount":418},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",{"slug":437,"name":438,"description":42,"image":42,"body":439,"postCount":330},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":441,"name":442,"description":42,"image":42,"body":443,"postCount":427},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":445,"name":446,"description":447,"image":42,"body":448,"postCount":409},"electrophoresis","Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":450,"name":451,"description":452,"image":42,"body":453,"postCount":330},"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":455,"name":456,"description":457,"image":42,"body":42,"postCount":330},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":459,"name":460,"description":461,"image":42,"body":42,"postCount":330},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":463,"name":464,"description":465,"image":42,"body":42,"postCount":330},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":467,"name":468,"description":469,"image":42,"body":42,"postCount":470},"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":472,"name":473,"description":474,"image":42,"body":42,"postCount":409},"biosafety-levels","Biosafety levels ","Articles related to Biosafety Levels",{"slug":476,"name":477,"description":478,"image":42,"body":42,"postCount":387},"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":480,"name":481,"description":482,"image":42,"body":42,"postCount":330},"pipette","Pipette","Posts related with Pipette. ",{"slug":484,"name":485,"description":486,"image":42,"body":42,"postCount":392},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":488,"name":489,"description":490,"image":42,"body":42,"postCount":491},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":493,"name":494,"description":495,"image":42,"body":42,"postCount":496},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":498,"name":499,"description":500,"image":42,"body":42,"postCount":387},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",{"slug":502,"name":503,"description":504,"image":42,"body":42,"postCount":392},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":506,"name":507,"description":508,"image":42,"body":42,"postCount":336},"microbial-curiosities","Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":510,"name":511,"description":512,"image":42,"body":42,"postCount":418},"bacterial-culture-media","Bacterial Culture Media","Posts related to Bacterial Culture Media. ",{"slug":514,"name":515,"description":516,"image":42,"body":42,"postCount":330},"fungal-culture-media","Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":518,"name":519,"description":520,"image":42,"body":42,"postCount":387},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":522,"name":523,"description":524,"image":42,"body":42,"postCount":427},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":526,"name":527,"description":528,"image":42,"body":42,"postCount":491},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":530,"name":531,"description":532,"image":42,"body":42,"postCount":496},"dimorphic-fungi","Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":534,"name":535,"description":536,"image":42,"body":42,"postCount":409},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":538,"name":539,"description":540,"image":42,"body":42,"postCount":387},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":542,"name":543,"description":544,"image":42,"body":42,"postCount":336},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":546,"name":547,"description":548,"image":42,"body":42,"postCount":409},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":550,"name":551,"description":42,"image":42,"body":42,"postCount":552},"haemophilus","Haemophilus",3,{"slug":554,"name":555,"description":556,"image":42,"body":42,"postCount":496},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":558,"name":559,"description":560,"image":42,"body":42,"postCount":377},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",{"slug":562,"name":563,"description":564,"image":42,"body":42,"postCount":371},"fungal-diagnostics","Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":150,"name":566,"description":567,"image":42,"body":42,"postCount":387},"Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":569,"name":570,"description":571,"image":42,"body":572,"postCount":330},"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":574,"name":575,"description":576,"image":42,"body":42,"postCount":392},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":578,"name":579,"description":580,"image":42,"body":42,"postCount":330},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":582,"name":583,"description":584,"image":42,"body":42,"postCount":330},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":586,"name":587,"description":588,"image":42,"body":42,"postCount":341},"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":126,"name":590,"description":591,"image":42,"body":42,"postCount":427},"Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":593,"name":594,"description":595,"image":42,"body":42,"postCount":325},"enzyme-tests","Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":597,"name":598,"description":599,"image":42,"body":42,"postCount":382},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",{"slug":601,"name":602,"description":603,"image":42,"body":42,"postCount":387},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":605,"name":606,"description":607,"image":42,"body":42,"postCount":496},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":609,"name":610,"description":611,"image":42,"body":42,"postCount":392},"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":613,"name":614,"description":615,"image":42,"body":42,"postCount":552},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":617,"name":618,"description":619,"image":42,"body":42,"postCount":387},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":621,"name":622,"description":623,"image":42,"body":42,"postCount":409},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":625,"name":626,"description":627,"image":42,"body":42,"postCount":496},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":629,"name":630,"description":631,"image":42,"body":42,"postCount":387},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":633,"name":634,"description":635,"image":42,"body":42,"postCount":409},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":637,"name":638,"description":639,"image":42,"body":42,"postCount":330},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":641,"name":642,"description":643,"image":42,"body":42,"postCount":409},"genetic-code","Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":645,"name":646,"description":647,"image":42,"body":42,"postCount":387},"molecular-technique","Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":649,"name":650,"description":42,"image":42,"body":42,"postCount":341},"colorimetric-assay","Colorimetric Assay ",{"slug":652,"name":653,"description":654,"image":42,"body":42,"postCount":387},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":656,"name":657,"description":42,"image":42,"body":42,"postCount":552},"blood-and-immune-cells","Blood and Immune Cells"]