[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fcGepx9lYegKHmxfAHAOWe5NWk8yrLB_O__ifN6Qxm7I":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":205,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":268},[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":56,"related":58,"comments":201},"bird-seed-agar-principle-composition-uses","Bird Seed Agar (Niger Seed Agar): Composition, Uses, and Cryptococcus Identification","\u003Cp>Bird seed agar selectively detects \u003Cem>Cryptococcus neoformans\u003C\u002Fem> by its brown-black melanin production from caffeic acid. Learn the principle, composition, colony appearance, and how it differentiates \u003Cem>C. neoformans\u003C\u002Fem> from other \u003Cem>Cryptococcus \u003C\u002Fem>species.\u003C\u002Fp>",null,"Nisha Rijal","2018-10-31","2026-08-17",false,"culture-media","A 32-year-old HIV-positive patient presents with severe headache, fever, and neck stiffness. CSF shows lymphocytic pleocytosis with elevated protein. [India ink](https:\u002F\u002Fmicrobeonline.com\u002Fcapsule-stain-principle-procedure-results\u002F) reveals yeast cells with large capsular halos. The CSF is inoculated onto bird seed agar (Niger seed agar \u002F Staib medium). After 72 hours at 30°C: brown-black colonies, melanin production from caffeic acid confirming *Cryptococcus neoformans*. A nearby colony of [*Candida albicans*](https:\u002F\u002Fmicrobeonline.com\u002Fcandida-albicans-pathogenesis-diagnosis\u002F) (contaminant) remains white.\n\nIn resource-limited settings where molecular identification is unavailable, bird seed agar provides a rapid, inexpensive, and specific presumptive identification of *Cryptococcus neoformans* from CSF, blood, and respiratory specimens. The melanin reaction distinguishes *C. neoformans* and *C. gattii* from all other yeasts.\n\nBird Seed Agar, also known as Staib medium, is a selective and differential medium for isolation of [***Cryptococcus neoformans***](https:\u002F\u002Fmicrobeonline.com\u002Fcryptococcus-neoformans-properties-pathogenesis-diseases-lab-diagnosis\u002F) from clinical specimens and differentiation of it from other *Cryptococcu*s species. It is also known as caffeic acid agar or niger seed agar. Due to the presence of phenoloxidase enzyme, *Cryptococcus* species can utilize various phenolic compounds as their substrate and produce dark brown, melanin-like pigments, thus presumptively identified.\n\nIn 1966, Shields and Ajello modified Staib’s bird seed agar by making the medium selective with an antimicrobial additive.\n\n![ - Colonies ofCryptococcus neoformansin birdseed agar](\u002Fblogs\u002Fcrypto-bird-seed-agar-e1540997362421.gif)Figure: Colonies of *Cryptococcus neoformans* in birdseed agar\n\n## Principle\n\nThe extract of Guizotia abyssinica seeds contains caffeic acid. Phenoloxidase enzyme produced by *Cryptococcus neoformans* utilizes caffeic acid as a substrate and produces melanin which in turn is absorbed by the yeast cell wall forming a tan to reddish-brown pigmentation. Glucose is the energy source in the medium. Creatinine enhances melanization of some strains of *Cryptococcus neoformans*. Agar is the solidifying agent. Chloramphenicol is added to inhibit the growth of bacteria and fast-growing fungi.\n\n**The melanin mechanism in detail:** *Cryptococcus neoformans* possesses the enzyme **laccase** (phenol oxidase), which oxidizes diphenolic compounds, particularly caffeic acid (present in the Niger seed\u002Fbird seed extract) to melanin. This melanin deposits in the cell wall, producing the distinctive brown-black colony color. Most other pathogenic yeasts, including *Candida* species, *Saccharomyces*, and non-*neoformans* Cryptococcus species (except *C. gattii*), lack laccase and therefore remain white or cream-colored on bird seed agar.\n\nThis melanin production is also a virulence factor, as discussed in the [pigments article](\u002Fpathogenic-microbes-characteristics-pigments-production\u002F).\n\n## Composition\n\n| Ingredients | Gm \u002F Litre |\n| --- | --- |\n| Guizotia abyssinica seeds | 70g |\n| Creatinine | 0.780g |\n| Dextrose | 10g |\n| Chloramphenicol | 0.050g |\n| Agar | 20g |\n| Final pH ( at 25°C) 6.7±0.2 |  |\n\n## Procedure for preparation of media\n\n1. Suspend required quantity (as per manufacturer’s instruction) of powder media in 1 liter of distilled water.\n2. Heat to boiling to dissolve the medium completely.\n3. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes.\n4. Cool to 45°C and add 100 mcg diphenyl per ml of medium (1 ml of sterile 1% w\u002Fv aqueous solution of diphenyl).\n5. Mix well and pour into sterile Petri plates.\n\n**NOTE:** The composition and method for media preparation vary according to the manufacturer. Some media contain pre-added phosphate and other antibiotics like penicillin G, gentamicin, while others need supplements to be added.\n\n## Interpretation of results\n\nPlates inoculated with suspected samples are observed after incubation at 30°C for 2 weeks. The presence of golden brown to black pigmented smooth colonies is indicative of *Cryptococcus neoformans*. Other species like *Cryptococcus laurentii,* *Saccharomyces cerevisiae,* etc produce non-pigmented colonies. *Candida* appears as white colonies.\n\n**Uses**\n\nBird Seed Agar is used for the selective isolation of *Cryptococcus neoformans* and *Cryptococcus gattii.*\n\n## *Cryptococcus* Species on Bird Seed Agar\n\n| Species | Colony Colour on BSA | Clinical Significance |\n| --- | --- | --- |\n| *C. neoformans* var. *grubii* (serotype A) | **Brown-black** | Most common; AIDS-associated cryptococcal meningitis worldwide |\n| *C. neoformans* var. *neoformans* (serotype D) | **Brown-black** | Less common; immunocompromised patients |\n| *C. gattii* (serotypes B and C) | **Brown-black** | Affects immunocompetent hosts; tree-associated (eucalyptus); Pacific Northwest and tropics |\n| *C. laurentii* | White\u002Fcream | Non-pathogenic; no laccase |\n| *C. albidus* | White\u002Fcream | Non-pathogenic; no laccase |\n| *Candida* spp. | White\u002Fcream | Negative on BSA |\n| *Rhodotorula* spp. | **Salmon\u002Forange** (own pigment) | Non-melanin pigment; distinct from *Cryptococcus* brown |\n\n**Key point:** Both *C. neoformans* and *C. gattii* produce brown-black colonies on bird seed agar, they cannot be differentiated from each other by this medium alone. CanaVanine-Glycine-Bromothymol (CGB) agar or molecular methods are needed to distinguish these two species.\n\n**Quality control**\n\n- *Cryptococcus neoformans* ATCC 32045 can be used as a **positive control** that shows brown to black pigmented colonies.\n- *Escherichia coli* ATCC 25922 can be used as a **negative control** in which growth is inhibited partially or completely.\n\n## Key Exam Facts in One Table\n\n| Feature | Detail |\n| --- | --- |\n| Also called | Niger seed agar, Staib medium, birdseed agar |\n| Named after | Walter Staib (developed the medium) |\n| Key substrate | Caffeic acid (from *Guizotia abyssinica* Niger seeds) |\n| Reaction | Laccase (phenol oxidase) oxidises caffeic acid → melanin |\n| *C. neoformans* appearance | Brown-black colonies at 72h–5 days |\n| *C. gattii* appearance | Brown-black (same as *C. neoformans*) |\n| *Candida* appearance | White\u002Fcream, no melanin |\n| *Rhodotorula* appearance | Salmon\u002Forange (own pigment), not melanin |\n| Distinguishes | *C. neoformans\u002Fgattii* from all other clinically important yeasts |\n| Does NOT distinguish | *C. neoformans* from *C. gattii* — need CGB agar or molecular |\n| Incubation | 25–30°C; 72h–5 days |\n| Clinical use | CSF, blood, respiratory specimens in *Cryptococcus*-suspected cases |\n| Melanin as virulence factor | Laccase protects from oxidative killing; may reduce amphotericin B efficacy |\n\n**References and further readings**\n\n1. Acharya T., Hare J. (2022) Sabouraud Agar, and Other Fungal Growth Media. In: Gupta V.K., Tuohy M. (eds) Laboratory Protocols in Fungal Biology. Fungal Biology. Springer, Cham. [https:\u002F\u002Fdoi.org\u002F10.1007\u002F978-3-030-83749-5_2](https:\u002F\u002Flink.springer.com\u002Fbook\u002F10.1007\u002F978-3-030-83749-5)\n2. Staib F. Cryptococcus neoformans und Guizotia abyssinica (syn. G. oleifera DC). Z Hyg Infektionskr. 1962;148:466–475. (Original description of the medium.)\n3. Kwon-Chung KJ, Bennett JE. Medical Mycology. Lea & Febiger; 1992.\n4. Larone DH. Larone's Medically Important Fungi: A Guide to Identification. 6th ed. ASM Press; 2018.\n5. Perfect JR, Dismukes WE, Dromer F, et al. Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the Infectious Diseases Society of America. Clin Infect Dis. 2010;50(3):291–322. \u003Chttps:\u002F\u002Fdoi.org\u002F10.1086\u002F649858>\n6. Murray PR, Rosenthal KS, Pfaller MA. Medical Microbiology. 9th ed. Elsevier; 2020.",[50,53],{"question":51,"answer":52},"\u003Cp>How does bird seed agar identify \u003Cem>Cryptococcus neoformans\u003C\u002Fem>?\u003C\u002Fp>","\u003Cp>Bird seed agar (Niger seed\u002FStaib medium) contains caffeic acid derived from Guizotia abyssinica (Niger seeds). \u003Cem>Cryptococcus neoformans\u003C\u002Fem> possesses the enzyme laccase (phenol oxidase), which oxidises caffeic acid to melanin. This melanin deposits in the cell wall, producing distinctive brown-black colonies within 72 hours to 5 days at 30°C. Most other pathogenic yeasts, including all \u003Cem>Candida\u003C\u002Fem> species, lack laccase and remain white or cream colored. The brown-black colony color on bird seed agar is essentially diagnostic for \u003Cem>Cryptococcus neoformans\u003C\u002Fem> or \u003Cem>C. gattii\u003C\u002Fem> (both possess laccase) in the clinical laboratory.\u003C\u002Fp>",{"question":54,"answer":55},"\u003Cp>Can bird seed agar differentiate \u003Cem>Cryptococcus neoformans\u003C\u002Fem> from \u003Cem>Cryptococcus gattii\u003C\u002Fem>?\u003C\u002Fp>","\u003Cp>No. Both \u003Cem>C. neoformans\u003C\u002Fem> and \u003Cem>C. gattii \u003C\u002Fem>produce laccase and give identical brown-black colonies on bird seed agar. They cannot be differentiated by this medium alone. Differentiation requires CanaVanine-Glycine-Bromothymol blue (CGB) agar: \u003Cem>C. gattii \u003C\u002Fem>grows on CGB agar and turns the medium blue (produces ammonia from glycine), while \u003Cem>C. neoformans \u003C\u002Fem>does not grow on CGB. This distinction matters clinically because \u003Cem>C. gattii \u003C\u002Fem>primarily infects immunocompetent hosts (unlike\u003Cem> C. neoformans\u003C\u002Fem> which predominantly causes disease in immunocompromised patients), affects different geographic areas, and may respond differently to antifungal therapy.\u003C\u002Fp>",[57],"fungal-culture-media",[59,76,109,132,142,157,165,178],{"slug":60,"title":61,"description":62,"seoTitle":42,"seoDescription":42,"author":63,"createdDate":64,"lastUpdatedDate":65,"draft":46,"category":66,"image":42,"faq":67,"tags":74},"capsule-stain-principle-procedure-results","Capsule Stain: Principle, Procedure, and Results","\u003Cp>Capsule staining detects bacterial capsules. Learn the India ink and Anthony's methods, clinically important capsulated organisms, and the Quellung reaction for pneumococcal identification.\u003C\u002Fp>","Acharya Tankeshwar","2016-10-15","2026-08-21","staining-techniques",[68,71],{"question":69,"answer":70},"Why can bacterial capsules not be stained directly?","\u003Cp>Bacterial capsules are composed primarily of polysaccharides (occasionally polypeptides), which are non-ionic. Since conventional dyes are either cationic (basic dyes) or anionic (acidic dyes), they have no charged surface to bind to on the capsule. \u003Cbr>\u003Cbr>Capsule staining is therefore always indirect: the bacterial cell is stained with a basic dye and the background is stained with an acidic dye, revealing the capsule as an unstained clear halo between them.\u003C\u002Fp>",{"question":72,"answer":73},"\u003Cp>How is India ink used to diagnose Cryptococcal meningitis?\u003C\u002Fp>","\u003Cp>India ink (or nigrosin) is mixed with a drop of CSF on a microscope slide and examined under oil immersion. \u003Cem>Cryptococcus neoformans \u003C\u002Fem>appears as a yeast cell (round to oval, 4-20 μm) surrounded by a clear capsule halo against the dark ink background. The halo can be dramatically large relative to the cell body. \u003Cbr>\u003Cbr>India ink is a rapid, inexpensive bedside diagnostic test with approximately 50-80% sensitivity in cryptococcal meningitis. A negative India ink does not exclude cryptococcal meningitis; the cryptococcal antigen latex agglutination test is more sensitive and should be performed when clinical suspicion is high.\u003C\u002Fp>",[75],"bacterial-staining-technique",{"slug":77,"title":78,"description":79,"seoTitle":42,"seoDescription":42,"author":63,"createdDate":80,"lastUpdatedDate":45,"draft":46,"category":81,"image":42,"faq":82,"tags":107},"candida-albicans-pathogenesis-diagnosis","Candida albicans: Gram Stain, Morphology, Pathogenesis, and Lab Diagnosis","\u003Cp>\u003Cem>Candida albicans \u003C\u002Fem>stains Gram-positive and appears as budding yeast cells with pseudohyphae. Learn its microscopy, why it stains as it does, virulence and pathogenesis, the diseases it causes, and how it is identified in the lab.\u003C\u002Fp>","2016-03-14","mycology",[83,86,89,92,95,98,101,104],{"question":84,"answer":85},"\u003Cp>Is \u003Cem>Candida albicans\u003C\u002Fem> Gram-positive or Gram-negative?\u003C\u002Fp>","\u003Cp>It stains Gram-positive (purple). But \u003Cem>Candida\u003C\u002Fem> is a yeast, not a bacterium, and has no peptidoglycan cell wall, so it is best understood as a yeast that stains Gram-positive rather than a true Gram-positive bacterium. Its staining can be uneven (Gram-variable).\u003C\u002Fp>",{"question":87,"answer":88},"\u003Cp>What does\u003Cem> Candida albicans\u003C\u002Fem> look like under the microscope?\u003C\u002Fp>","\u003Cp>Oval budding yeast cells (blastoconidia) about 3 to 6 micrometers, often with pseudohyphae, which are chains of elongated cells with constrictions at the junctions. In tissue it can also form true hyphae.\u003C\u002Fp>",{"question":90,"answer":91},"\u003Cp>What is the difference between pseudohyphae and true hyphae?\u003C\u002Fp>","\u003Cp>Pseudohyphae are chains of elongated yeast cells with constrictions where the cells join. True hyphae have parallel walls and no constrictions.\u003C\u002Fp>",{"question":93,"answer":94},"\u003Cp>How is \u003Cem>Candida albicans\u003C\u002Fem> identified in the lab?\u003C\u002Fp>","\u003Cp>Presumptively by a positive germ tube test and \"feet\" on blood agar, and by chlamydospore formation on cornmeal agar. Definitive identification uses automated systems, MALDI-TOF, or molecular methods.\u003C\u002Fp>",{"question":96,"answer":97},"\u003Cp>What is the germ tube test?\u003C\u002Fp>","\u003Cp>A rapid presumptive test where \u003Cem>Candida albicans\u003C\u002Fem> forms a short hyphal outgrowth in serum. A positive result suggests \u003Cem>C. albicans\u003C\u002Fem>, though \u003Cem>C. dubliniensis\u003C\u002Fem> can also be positive.\u003C\u002Fp>",{"question":99,"answer":100},"\u003Cp>What diseases does \u003Cem>Candida albicans\u003C\u002Fem> cause?\u003C\u002Fp>","\u003Cp>Oral thrush, vaginal thrush, skin and nail infections, and, in immunocompromised or seriously ill patients, candidemia and disseminated infection affecting deep organs.\u003C\u002Fp>",{"question":102,"answer":103},"\u003Cp>How is \u003Cem>Candida\u003C\u002Fem> infection treated?\u003C\u002Fp>","\u003Cp>Mucocutaneous disease is treated with topical or oral azoles. Invasive candidiasis and candidemia are treated first-line with an echinocandin. Some species, such as \u003Cem>C. krusei\u003C\u002Fem> and \u003Cem>C. auris\u003C\u002Fem>, are drug-resistant, so identification guides treatment.\u003C\u002Fp>",{"question":105,"answer":106},"\u003Cp>Why can \u003Cem>Candida\u003C\u002Fem> be mistaken for \u003Cem>Staphylococcus\u003C\u002Fem> on culture?\u003C\u002Fp>","\u003Cp>On blood agar both can form creamy white colonies. A Gram stain or wet mount quickly distinguishes them, since \u003Cem>Candida\u003C\u002Fem> shows large budding yeast cells rather than clusters of cocci. This matters most with high vaginal swabs.\u003C\u002Fp>",[108],"fungal-diagnostics",{"slug":110,"title":111,"description":112,"seoTitle":42,"seoDescription":42,"author":63,"createdDate":113,"lastUpdatedDate":114,"draft":46,"category":81,"image":42,"faq":115,"tags":131},"cryptococcus-neoformans-properties-pathogenesis-diseases-lab-diagnosis","Cryptococcus neoformans: Pathogenesis, Lab Diagnosis","\u003Cp>\u003Cem>Cryptococcus neoformans\u003C\u002Fem> and \u003Cem>C. gattii:\u003C\u002Fem> capsule and melanin virulence, narrow-based budding, why it causes fungal meningitis in HIV\u002FAIDS, and lab diagnosis by India ink, birdseed agar, and the cryptococcal antigen (CrAg) test.\u003C\u002Fp>","2016-05-16","2026-08-25",[116,119,122,125,128],{"question":117,"answer":118},"\u003Cp>How is \u003Cem>Cryptococcus\u003C\u002Fem> different from \u003Cem>Candida\u003C\u002Fem> on microscopy?\u003C\u002Fp>","\u003Cp>\u003Cem>Cryptococcus\u003C\u002Fem> is an encapsulated yeast with narrow-based budding and no pseudohyphae, and it shows a clear halo on India ink. \u003Cem>Candida\u003C\u002Fem> has no significant capsule, buds without the narrow neck, and forms pseudohyphae (and true hyphae for some species). The capsule and the absence of pseudohyphae are the quickest distinguishing features.\u003C\u002Fp>",{"question":120,"answer":121},"\u003Cp>Why does \u003Cem>Cryptococcus\u003C\u002Fem> cause meningitis specifically?\u003C\u002Fp>","It is neurotropic: after inhalation and pulmonary infection, it preferentially disseminates to the central nervous system in people with impaired T-cell immunity. Its capsule lets it evade phagocytosis, and the minimal inflammatory response in the brain allows it to grow relatively unchecked, producing subacute or chronic meningitis.",{"question":123,"answer":124},"\u003Cp>What is the difference between \u003Cem>C. neoformans\u003C\u002Fem> and \u003Cem>C. gattii\u003C\u002Fem>?\u003C\u002Fp>","\u003Cp>\u003Cem>C. neoformans\u003C\u002Fem> is found in bird droppings and infects mainly immunocompromised people, especially those with advanced HIV. \u003Cem>C. gattii\u003C\u002Fem> is associated with trees, has a more tropical distribution (with a known outbreak in the Pacific Northwest), and characteristically infects immunocompetent people. They are separated in the lab on CGB agar, which \u003Cem>C. gattii\u003C\u002Fem> turns blue.\u003C\u002Fp>",{"question":126,"answer":127},"Why has the CrAg test replaced India ink?","India ink is cheap and fast but detects the organism in fewer than half of cases and depends on the observer's experience. The cryptococcal antigen (CrAg) test, especially the lateral flow assay, is far more sensitive and specific, works on blood as well as CSF, needs no special equipment, and can even detect infection before symptoms appear in high-risk HIV patients.",{"question":129,"answer":130},"\u003Cp>Why does \u003Cem>Cryptococcus\u003C\u002Fem> grow black on birdseed agar?\u003C\u002Fp>","\u003Cp>\u003Cem>Cryptococcus neoformans\u003C\u002Fem> produces the enzyme phenoloxidase, which converts substrates in birdseed (niger seed) agar into melanin, turning the colonies brown to black. This is a rapid presumptive identification, and the same melanin production is one of the organism's virulence factors.\u003C\u002Fp>",[108],{"slug":133,"title":134,"description":135,"seoTitle":42,"seoDescription":42,"author":63,"createdDate":136,"lastUpdatedDate":137,"draft":46,"category":138,"image":42,"faq":139,"tags":140},"pathogenic-microbes-characteristics-pigments-production","Bacterial and Fungal Pigments: Identification Clues and Virulence Factors","Which organisms produce which pigments and on what medium, from pyocyanin and prodigiosin to staphyloxanthin and melanin, plus why several of these pigments are active virulence factors rather than metabolic byproducts.","2016-04-13","2026-07-24","general-microbiology",[],[141],"microbial-curiosities",{"slug":143,"title":144,"description":145,"seoTitle":42,"seoDescription":42,"author":146,"createdDate":147,"lastUpdatedDate":148,"draft":46,"category":47,"image":42,"faq":149,"tags":156},"czapek-dox-agar-principle-composition-colony-characteristics","Czapek Dox Agar: Composition, Principle, and Colony Characteristics of Aspergillus and Penicillium","Czapek Dox agar is a synthetic medium with sucrose as the sole carbon source and nitrate as the sole nitrogen source — used for identification of Aspergillus, Penicillium, and other environmental fungi.","Sushmita Baniya","2022-06-11","2026-07-13",[150,153],{"question":151,"answer":152},"What makes Czapek Dox agar different from Sabouraud dextrose agar for fungal identification?","Czapek Dox agar is a synthetic (chemically defined) medium with sucrose as the sole carbon source and sodium nitrate as the sole nitrogen source — providing minimal, standardised nutrition. Sabouraud dextrose agar contains peptone as a complex nitrogen source, supporting more luxuriant growth. On Czapek Dox, the nutritional restriction reveals phenotypic differences in colony texture, colour, and growth rate that are suppressed on richer media. This makes Czapek Dox particularly useful for taxonomic characterisation of Aspergillus and Penicillium species, where colony morphology on a defined medium is part of the formal species description. It is not used for primary isolation from clinical specimens as it does not support fastidious organisms.",{"question":154,"answer":155},"Which fungi are best identified on Czapek Dox agar?","Czapek Dox agar is primarily used for identification of Aspergillus and Penicillium species — both common environmental moulds that may cause opportunistic infections in immunocompromised patients. On Czapek Dox, Aspergillus fumigatus produces characteristic blue-grey to grey-green colonies, A. flavus produces yellow-green colonies with granular texture, and A. niger produces dense black colonies. Penicillium species produce characteristic blue-green powdery colonies with the brush-like conidiophore arrangement visible on LPCB mount. The standardised composition ensures reproducible colony morphology that matches published species descriptions used in formal identification.",[57],{"slug":158,"title":159,"description":160,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":161,"lastUpdatedDate":162,"draft":46,"category":47,"image":42,"faq":163,"tags":164},"sabouraud-dextrose-agar-sda-principle-composition-uses-colony-morphology","Sabouraud Dextrose Agar (SDA): Composition, Principle, Uses, and Colony Morphology","Sabouraud Dextrose Agar (SDA) is the standard medium for fungal isolation. Learn its composition, how its acidic pH selects for fungi, colony morphology of dermatophytes and yeasts, cycloheximide modification, and clinical uses.","2015-07-05","2026-08-03",[],[57],{"slug":166,"title":167,"description":168,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":169,"lastUpdatedDate":114,"draft":46,"category":47,"image":42,"faq":170,"tags":177},"potato-dextrose-agar-pda-principle-composition-colony-characteristics","Potato Dextrose Agar (PDA): Composition, Preparation, Uses, and Fungal Colony Characteristics","Potato dextrose agar promotes sporulation in fungi that fail to produce conidia on richer media. Learn the composition, why potato infusion induces sporulation, typical colony characteristics of dermatophytes, and how PDA compares to Sabouraud agar.","2015-06-01",[171,174],{"question":172,"answer":173},"Why does potato dextrose agar induce better sporulation than Sabouraud dextrose agar in some fungi?","\u003Cp>PDA provides a nutritionally restricted environment: the potato infusion is low in amino acids and complex growth factors compared to the peptone-rich Sabouraud agar. This nutritional restriction creates metabolic stress that triggers fungi to reproduce by sporulation as a survival mechanism.\u003C\u002Fp>\u003Cp>\u003C\u002Fp>\u003Cp>On richer media like blood agar or BHI, the same fungi grow lush vegetative mycelium without sporulating. The 2% dextrose in PDA provides sufficient carbon for sustained growth, while the restricted nitrogen from potato infusion delivers the stress signal. This is why PDA is the preferred medium for inducing sporulation in dermatophytes that fail to produce diagnostic conidia on standard media.\u003C\u002Fp>",{"question":175,"answer":176},"What is the diagnostic significance of red\u002Fwine-coloured reverse pigment on PDA?","\u003Cp>A characteristic red to wine-red reverse pigment on the underside of colonies on PDA is highly characteristic of \u003Cem>Trichophyton rubrum\u003C\u002Fem>: the most common cause of tinea pedis (athlete's foot), tinea unguium (onychomycosis), and tinea corporis worldwide. \u003C\u002Fp>\u003Cp>\u003C\u002Fp>\u003Cp>This red reverse pigment is more prominently expressed on PDA than on Sabouraud agar, making PDA subculture valuable for confirming \u003Cem>T. rubrum\u003C\u002Fem> identity when reverse pigment is absent or faint on primary isolation plates. In combination with the microscopic appearance (thin-walled pencil-shaped macroconidia and tear-drop microconidia) and clinical presentation, the red reverse on PDA is an important identification feature.\u003C\u002Fp>",[57],{"slug":179,"title":180,"description":181,"seoTitle":42,"seoDescription":42,"author":63,"createdDate":182,"lastUpdatedDate":65,"draft":46,"category":81,"image":42,"faq":183,"tags":199},"dermatophyte-test-medium-dtm-composition-preparation-and-uses","Dermatophyte Test Medium (DTM): Composition, Preparation, and the Pathogens It Can Miss","Why a clean, unchanged DTM tube after two weeks doesn't always mean no fungal infection, the color-change logic explained, and the one ingredient that can silently suppress a true pathogen along with the contaminants.","2021-01-30",[184,187,190,193,196],{"question":185,"answer":186},"What is Dermatophyte Test Medium (DTM) used for?","Screening for dermatophytes (ringworm-causing fungi) in samples like hair, skin scrapings, or nail clippings, using a color change from yellow to red\u002Fpink as the presumptive positive signal.",{"question":188,"answer":189},"Why does DTM turn red when dermatophytes grow?","Dermatophyte metabolism shifts the medium's pH alkaline, and the phenol red indicator turns pink at pH ≥ 8.2. Saprophytic fungi, by contrast, ferment sugars into acid and leave the medium yellow.",{"question":191,"answer":192},"Can DTM give a false negative result?","Yes. Cycloheximide, included to suppress saprophytic contaminants, can also suppress genuine pathogenic fungi that happen to be cycloheximide-sensitive, producing a \"no growth\" result indistinguishable from a true negative.",{"question":194,"answer":195},"Should DTM be used as the only fungal culture medium?","No. It should be paired with a cycloheximide-free medium whenever a broader fungal differential is clinically relevant, to avoid missing a cycloheximide-sensitive true pathogen.",{"question":197,"answer":198},"Why should DTM results be read within two weeks?","Because incubation beyond two weeks increases the risk of false positives, as slow-growing saprophytic fungi can eventually produce alkaline byproducts too.",[57,200],"dermatophytes",{"enabled":202,"threads":203,"total":204},true,[],0,[206,212,219,225,231,236,242,247,253,256,262],{"slug":207,"name":63,"description":208,"image":209,"body":210,"postCount":211},"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.*",481,{"slug":213,"name":214,"description":215,"image":216,"body":217,"postCount":218},"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.",79,{"slug":220,"name":146,"description":221,"image":222,"body":223,"postCount":224},"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":226,"name":227,"description":221,"image":228,"body":229,"postCount":230},"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":232,"name":233,"description":221,"image":42,"body":234,"postCount":235},"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":237,"name":238,"description":239,"image":42,"body":240,"postCount":241},"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":243,"name":244,"description":245,"image":42,"body":42,"postCount":246},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":248,"name":249,"description":221,"image":250,"body":251,"postCount":252},"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.",15,{"slug":254,"name":255,"description":245,"image":42,"body":42,"postCount":246},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":257,"name":43,"description":258,"image":259,"body":260,"postCount":261},"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":263,"name":264,"description":265,"image":266,"body":267,"postCount":246},"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.",[269,276,282,287,292,297,301,305,309,314,318,323,327,332,337,341,345,349,354,359,363,367,371,376,380,384,388,392,397,402,406,410,413,418,421,425,429,433,437,441,445,449,453,457,461,465,468,472,477,481,485,489,493,496,500,504,508,512,516,520,524,528,532,536,540,544,548,552,555,559,562,565,568,571,574,577,579,582,585,588,591,594,597],{"slug":270,"name":271,"description":272,"image":273,"body":274,"postCount":275},"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":277,"name":278,"description":279,"image":42,"body":280,"postCount":281},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":283,"name":284,"description":285,"image":42,"body":42,"postCount":286},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",11,{"slug":288,"name":289,"description":290,"image":42,"body":42,"postCount":291},"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":293,"name":294,"description":295,"image":42,"body":42,"postCount":296},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":298,"name":299,"description":300,"image":42,"body":42,"postCount":286},"mycobacteria","Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":302,"name":303,"description":304,"image":42,"body":42,"postCount":281},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":306,"name":307,"description":308,"image":42,"body":42,"postCount":281},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":310,"name":311,"description":312,"image":42,"body":42,"postCount":313},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":315,"name":316,"description":317,"image":42,"body":42,"postCount":275},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":319,"name":320,"description":321,"image":42,"body":42,"postCount":322},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",21,{"slug":324,"name":325,"description":326,"image":42,"body":42,"postCount":275},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":328,"name":329,"description":330,"image":42,"body":42,"postCount":331},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":333,"name":334,"description":335,"image":42,"body":42,"postCount":336},"specimen-collection-transport","Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":338,"name":339,"description":340,"image":42,"body":42,"postCount":322},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",{"slug":342,"name":343,"description":42,"image":42,"body":344,"postCount":235},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":346,"name":347,"description":42,"image":42,"body":348,"postCount":331},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":350,"name":351,"description":352,"image":42,"body":353,"postCount":313},"electrophoresis","Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":355,"name":356,"description":357,"image":42,"body":358,"postCount":235},"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":360,"name":361,"description":362,"image":42,"body":42,"postCount":235},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":364,"name":365,"description":366,"image":42,"body":42,"postCount":235},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":368,"name":369,"description":370,"image":42,"body":42,"postCount":235},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":372,"name":373,"description":374,"image":42,"body":42,"postCount":375},"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":377,"name":378,"description":379,"image":42,"body":42,"postCount":313},"biosafety-levels","Biosafety levels ","Articles related to Biosafety Levels",{"slug":381,"name":382,"description":383,"image":42,"body":42,"postCount":291},"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":385,"name":386,"description":387,"image":42,"body":42,"postCount":235},"pipette","Pipette","Posts related with Pipette. ",{"slug":389,"name":390,"description":391,"image":42,"body":42,"postCount":296},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":393,"name":394,"description":395,"image":42,"body":42,"postCount":396},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":398,"name":399,"description":400,"image":42,"body":42,"postCount":401},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":403,"name":404,"description":405,"image":42,"body":42,"postCount":291},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",{"slug":407,"name":408,"description":409,"image":42,"body":42,"postCount":296},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":141,"name":411,"description":412,"image":42,"body":42,"postCount":241},"Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":414,"name":415,"description":416,"image":42,"body":42,"postCount":417},"bacterial-culture-media","Bacterial Culture Media","Posts related to Bacterial Culture Media. ",23,{"slug":57,"name":419,"description":420,"image":42,"body":42,"postCount":235},"Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":422,"name":423,"description":424,"image":42,"body":42,"postCount":291},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":426,"name":427,"description":428,"image":42,"body":42,"postCount":331},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":430,"name":431,"description":432,"image":42,"body":42,"postCount":396},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":434,"name":435,"description":436,"image":42,"body":42,"postCount":401},"dimorphic-fungi","Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":438,"name":439,"description":440,"image":42,"body":42,"postCount":313},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":442,"name":443,"description":444,"image":42,"body":42,"postCount":291},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":446,"name":447,"description":448,"image":42,"body":42,"postCount":241},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":450,"name":451,"description":452,"image":42,"body":42,"postCount":313},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":454,"name":455,"description":42,"image":42,"body":42,"postCount":456},"haemophilus","Haemophilus",3,{"slug":458,"name":459,"description":460,"image":42,"body":42,"postCount":401},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":462,"name":463,"description":464,"image":42,"body":42,"postCount":281},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",{"slug":108,"name":466,"description":467,"image":42,"body":42,"postCount":275},"Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":469,"name":470,"description":471,"image":42,"body":42,"postCount":291},"laboratory-storage-and-preservation","Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":473,"name":474,"description":475,"image":42,"body":476,"postCount":235},"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":478,"name":479,"description":480,"image":42,"body":42,"postCount":241},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":482,"name":483,"description":484,"image":42,"body":42,"postCount":235},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":486,"name":487,"description":488,"image":42,"body":42,"postCount":313},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":490,"name":491,"description":492,"image":42,"body":42,"postCount":246},"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":75,"name":494,"description":495,"image":42,"body":42,"postCount":331},"Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":497,"name":498,"description":499,"image":42,"body":42,"postCount":322},"enzyme-tests","Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":501,"name":502,"description":503,"image":42,"body":42,"postCount":286},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",{"slug":505,"name":506,"description":507,"image":42,"body":42,"postCount":291},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":509,"name":510,"description":511,"image":42,"body":42,"postCount":401},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":513,"name":514,"description":515,"image":42,"body":42,"postCount":296},"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":517,"name":518,"description":519,"image":42,"body":42,"postCount":456},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":521,"name":522,"description":523,"image":42,"body":42,"postCount":291},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":525,"name":526,"description":527,"image":42,"body":42,"postCount":313},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":529,"name":530,"description":531,"image":42,"body":42,"postCount":401},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":533,"name":534,"description":535,"image":42,"body":42,"postCount":291},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":537,"name":538,"description":539,"image":42,"body":42,"postCount":313},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":541,"name":542,"description":543,"image":42,"body":42,"postCount":235},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":545,"name":546,"description":547,"image":42,"body":42,"postCount":313},"genetic-code","Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":549,"name":550,"description":551,"image":42,"body":42,"postCount":313},"molecular-technique","Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":553,"name":554,"description":42,"image":42,"body":42,"postCount":246},"colorimetric-assay","Colorimetric Assay ",{"slug":556,"name":557,"description":558,"image":42,"body":42,"postCount":291},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":560,"name":561,"description":42,"image":42,"body":42,"postCount":456},"blood-and-immune-cells","Blood and Immune Cells",{"slug":563,"name":564,"description":42,"image":42,"body":42,"postCount":291},"host-pathogen-interaction","Host Pathogen Interaction",{"slug":566,"name":567,"description":42,"image":42,"body":42,"postCount":401},"blood-culture","Blood Culture",{"slug":569,"name":570,"description":42,"image":42,"body":42,"postCount":401},"environmental-microbiology","Environmental microbiology ",{"slug":572,"name":573,"description":42,"image":42,"body":42,"postCount":235},"copromicroscopic-technique","Copromicroscopic Technique",{"slug":575,"name":576,"description":42,"image":42,"body":42,"postCount":456},"quality-control","Quality Control",{"slug":200,"name":578,"description":42,"image":42,"body":42,"postCount":401},"Dermatophytes",{"slug":580,"name":581,"description":42,"image":42,"body":42,"postCount":456},"viral-hemorrhagic-fevers","Viral Hemorrhagic Fevers",{"slug":583,"name":584,"description":42,"image":42,"body":42,"postCount":401},"h2s-production","H2S Production",{"slug":586,"name":587,"description":42,"image":42,"body":42,"postCount":396},"water-quality-testing","Water Quality Testing",{"slug":589,"name":590,"description":42,"image":42,"body":42,"postCount":291},"virology-basics","Virology basics",{"slug":592,"name":593,"description":42,"image":42,"body":42,"postCount":401},"typing-methods","Typing Methods",{"slug":595,"name":596,"description":42,"image":42,"body":42,"postCount":456},"blotting-technique","Blotting Technique",{"slug":598,"name":599,"description":42,"image":42,"body":42,"postCount":401},"history-microbiology","History of Microbiology"]