Tests sucrose fermentation capability. Yellow color = sucrose fermented. Part of carbohydrate fermentation panels for bacterial ID. Recommended for Sucrose fermentation studies of microorganisms.
Tests mannitol fermentation. Yellow (acid) = positive. Used differentiating Staph aureus (positive) from other Staph in combination with MSA. Recommended for Mannitol fermentation studies of microorganisms.
Basic glucose fermentation test. Gas in Durham tube + yellow color = glucose fermentation. Baseline test for bacterial identification. Recommended for dextrose fermentation studies of microorganisms.
Tests esculin breakdown. Black color (esculin + iron) = positive. Esculin Agar is a differential medium for demonstrating esculin hydrolysis by various microorganisms
Tests ability to use sodium malonate as sole carbon source. Blue color (pH increase) = positive. Differentiates Enterobacter/Klebsiella (positive) from E. coli (negative).
Tests lipase enzyme (fat breakdown). Tributyrin (glyceryl tributyrate) in agar creates opaque medium. Clear zones around colonies = lipase activity. Used for identifying lipolytic bacteria and fungi.
Tests amylase enzyme (starch breakdown). After growth, flood with iodine - clear zone around colonies = starch hydrolysis (amylase present). Bacillus species typically positive. For detection of starch hydrolyzing microorganisms.
Tests gelatinase enzyme production. Organism liquefies gelatin. Used for identifying Serratia, Pseudomonas, Bacillus (positive) from non-gelatinase producers. For cultivation and identification of Vibrio species.
Tests ability to decarboxylate amino acids (lysine, ornithine, arginine). Purple color = positive (amine production raises pH). Used for Enterobacteriaceae differentiation. With addition of appropriate L-amino acid, it is used to differentiate bacteria on the basis of their ability to decarboxylate the amino acids.
Combination medium testing: Sulfide production (S), Indole production (I), Motility (M). Single stab inoculation tests 3 characteristics. Black = H2S, Red ring with Kovac's = indole, Diffuse growth = motility. For determination of hydrogen sulphide production, indole formation and motility of enteric bacilli.
ONPG (o-nitrophenyl-β-D-galactopyranoside) test detects beta-galactosidase enzyme. Organisms with beta-galactosidase cleave ONPG producing yellow o-nitrophenol. Used to differentiate late lactose fermenters from non-fermenters. Example: Citrobacter and some Salmonella possess beta-galactosidase but ferment lactose slowly on MacConkey. ONPG positive within hours. Shigella lacks enzyme (negative). Procedure: Inoculate heavy suspension in ONPG broth, incubate 35°C up to 24h. Yellow = positive. Used in enteric bacteria identification, helps differentiate Salmonella (usually negative) from Citrobacter (positive).
Phenylalanine Agar tests phenylalanine deaminase enzyme production. Organism deaminates phenylalanine to phenylpyruvic acid. After incubation on slant, add 10% ferric chloride - green color indicates phenylpyruvic acid (positive). Used for identifying: Proteus, Morganella, Providencia (all positive). Differentiates these from other Enterobacteriaceae (negative). Particularly useful for identifying Proteus species - positive reaction within 1-5 minutes of adding ferric chloride. Part of enteric bacteria identification schemes. Inoculate slant heavily, incubate 18-24h at 35°C.
DNase Test Agar tests production of deoxyribonuclease enzyme that degrades DNA. Contains DNA in agar. After incubation, flood plate with 1N HCl - unhydrolyzed DNA precipitates (cloudy/opaque). Clear zone around colonies = DNase positive. Used for: (1) S. aureus identification (positive), differentiates from coagulase-negative Staph (negative), (2) Serratia marcescens (positive), (3) Enterococcus faecalis testing. Clinical labs use for presumptive S. aureus - faster than coagulase test. Can also use with toluidine blue (no acid needed).
Plot No. C40, Road No. 21Y, MIDC, Wagle Industrial Estate, Thane(W)-400604, MH, India
