| agar | <cell culture, chemical, microbiology> This gelatinous material, an extract from red algae (mainly Gelidium and Gracilaria species), is most frequently used as a culture medium, especially for bacteria. It is also used as a thickener in foods, but humans cannot digest it. (06 May 1997) |
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| agar-gel reaction | <immunology> The reaction between an antibody and an antigen during an immunology lab procedure where the two are allowed to diffuse toward each other through an agar-gel medium. Lines of precipitation form in the places on the gel where the two react with each other and shows where the reaction has occurred. (09 Oct 1997) |
| ascitic agar | A form of serum agar. (05 Mar 2000) |
| bile salt agar | An agar medium containing lactose, peptone, sodium taurocholate, and neutral red, for the growth and isolation of Gram-negative rods. (05 Mar 2000) |
| birdseed agar | Media prepared from Guizottia abyssinica seeds used in culturing and in the presumptive diagnosis of Cryptococcus neoformans. (05 Mar 2000) |
| brain-heart infusion agar | A medium used for the isolation of fastidious microorganisms, especially fungi. (05 Mar 2000) |
| brilliant green salt agar | A highly selective culture medium consisting of agar with peptone, lactose, sodium taurocholate, brilliant green, and picric acid solution used in the primary isolation of enteric pathogens such as Salmonella species. (05 Mar 2000) |
| MacConkey agar | Medium containing peptone, lactose, bile salts, neutral red, and crystal violet used to identify Gram-negative bacilli and characterise them according to their status as lactose fermenters. Fermenters appear as red colonies while nonfermenters are colourless. (05 Mar 2000) |
| rice-Tween agar | A useful medium for the development of the differential chlamydospores in Candida albicans and for preparation of slide cultures for other forms of sporulation in other fungal species. (05 Mar 2000) |
| chocolate agar | Blood agar heated until the blood becomes brown or chocolate in colour, used especially to isolate Haemophilus influenza or Neisseria species. (05 Mar 2000) |
| cholera agar | An alkaline agar medium for cultivating Vibrio cholerae. (05 Mar 2000) |
| Guarnieri's gelatin agar | A type of agar, similar to Stoddart's gelatin agar, used for the cultivation of Streptococcus pneumoniae. (05 Mar 2000) |
| Mueller-Hinton agar | Medium containing beef infusion, peptone, and starch used primarily for the disk-agar diffusion method for antimicrobial susceptibility testing. (05 Mar 2000) |
| Conradi-Drigalski agar | A selective, nutrient medium for isolation of Salmonella typhi and other intestinal pathogens from faecal specimens; it contains the dye crystal violet, which generally inhibits growth of Gram-positive, but not Gram-negative, bacteria. Synonym: Drigalski-Conradi agar. (05 Mar 2000) |
| cornmeal agar | A culture medium that is low in nutrients, used extensively in the study of yeastlike and filamentous fungi; it suppresses vegetative growth while stimulating sporulation of many species, and is widely used for producing the distinctive and rapidly diagnostic chlamydospores of Candida albicans. (05 Mar 2000) |