Biochemical Test

Spot Indole Test- Objective, Principle, Procedure, Results and Limitations

Result Interpretation of Spot Indole Test

Objective of Spot Indole Test To determine the ability of organism for the production of indole by the action of tryptophanase enzyme. Principle of Spot Indole Test Intracellular enzyme tryptophanase mediate the production of indole by hydrolytic activity against amino acid Tryptophan. Bacteria that produce the enzyme tryptophanase are able to degrade the amino acid tryptophan into … Read moreSpot Indole Test- Objective, Principle, Procedure, Results and Limitations

Starch Hydrolysis Test- Objectives, Principle, Procedure and Results

Result interpretation of Starch Hydrolysis Test

Objectives of Starch Hydrolysis Test To determine the ability of the organism capable of hydrolyzing starch. To differentiate organism based on their ability to hydrolyze starch with the enzyme, α- amylase. It aids in the differentiation of species from genera Corynebacterium, Clostridium, Bacillus, Bacteroides, Fusobacterium, and members of Enterococcus. Principle of Starch Hydrolysis Test Starch is a complex … Read moreStarch Hydrolysis Test- Objectives, Principle, Procedure and Results

Oxidation-Fermentation (OF) Test

Result Interpretation of OF Test

Objective of OF Test To differentiate microorganisms based on the ability to oxidize or ferment specific carbohydrates. Principle of OF Test Carbohydrates are organic molecules that contain carbon, hydrogen and oxygen in the ratio (CH2O)n. Organisms use carbohydrate differently depending upon their enzyme complement. The pattern of fermentation is characteristics of certain species, genera or groups … Read moreOxidation-Fermentation (OF) Test

Oxidase Test- Principle, Procedure and Results

Result Interpretation of Oxidase Test

Objective of Oxidase Test To determine the ability of the organism to produce the cytochrome oxidase enzyme. Principle of Oxidase Test The oxidase test is designed for specifically detecting the presence of the terminal enzyme system in aerobic respiration called cytochrome C oxidase or cytochrome a3. Cytochrome C oxidase is the terminal or last H2 electron … Read moreOxidase Test- Principle, Procedure and Results

Novobiocin Susceptibility Test- Principle, Procedure and Results

Result Interpretation of Novobiocin Susceptibility Test

Objectives of Novobiocin Susceptibility Test To determine susceptibility pattern of bacterium to novobiocin. To distinguish or differentiate Staphylococcus saprophyticus from other coagulase-negative staphylococci. Principle of Novobiocin Susceptibility Test Novobiocin is an antibiotic interfering with the unpackaging and repackaging of DNA during DNA replication and the bacterial cell cycle. Novobiocin binds to DNA gyrase, and blocks adenosine triphosphatase (ATPase) activity.  Laboratory identification … Read moreNovobiocin Susceptibility Test- Principle, Procedure and Results

4-Methylumbelliferyl-β-D-Glucuronide (MUG) Test

4-Methylumbelliferyl-β-D-Glucuronide (MUG) Test

Objective of MUG Test To identify various genera of Enterobacteriaceae and verotoxin-producing Escherichia coli. Principle of MUG Test β-D-Glucuronidase is an enzyme produced by most strains of E. coli and other Enterobacteriaceae  which hydrolyzes β-d-glucopyranosid-uronic derivatives to aglycons and d-glucuronic acid. The substrate 4-methylumbelliferyl-beta-D-glucuronide is impregnated in the disc. MUG is an acronym for 4-methylumbelliferyl-beta-D-glucuronide, a … Read more4-Methylumbelliferyl-β-D-Glucuronide (MUG) Test

MRS Broth Test- Principle, Procedure and Results

Result Interpretation of MRS Broth Test

Objectives of MRS Broth Test It is used for the cultivation and enumeration of lactobacilli in a laboratory setting To determine the ability of organism to form gas during glucose fermentation Principle of MRS Broth Test MRS Broth is an improved medium for lactobacilli, it supports good growth and is particularly useful for a number of fastidious strains … Read moreMRS Broth Test- Principle, Procedure and Results

O-Nitrophenyl-β-D-Galactopyranoside (ONPG) Test

O-Nitrophenyl-β-D-Galactopyranoside (ONPG) Test

Objectives of ONPG Test To determine the ability of an organism to produce β-galactosidase, an enzyme that hydrolyzes the substrate ONPG to form a visible (yellow) product, orthonitrophenol To distinguish late lactose fermenters from non–lactose fermenters of Enterobacteriaceae Principle of ONPG Test The sugar lactose is a disaccharide of galactose and glucose joined by a β-galactoside … Read moreO-Nitrophenyl-β-D-Galactopyranoside (ONPG) Test

Motility Test- Principle, Procedure and Results

Motility Test- Principle, Procedure and Results

Objectives of Motility Test To determine the motility of bacterium. To differentiate between motile and non motile bacteria. Principle of Motility Test Motility is the ability of an organism to move by itself by means of propeller-like flagella unique to bacteria or by special fibrils that produce a gliding form of motility. Motile  bacteria  move  using   flagella, … Read moreMotility Test- Principle, Procedure and Results

Optochin Susceptibility Test- Principle, Procedure and Results

Optochin Susceptibility Test- Principle, Procedure and Results

Objectives of Optochin Susceptibility Test To determine the effect of Optochin (ethyl hydrocupreine hydrochloride) on an organism. To differentiate between alpha hemolytic Streptococcus pneumoniae from other alpha hemolytic viridans Streptococci. Principle of Optochin Susceptibility Test Optochin (ethylhydrocupreine hydrochloride) is a chemical and is completely soluble in water. Optochin is an antibiotic that interferes with the ATPase and production of … Read moreOptochin Susceptibility Test- Principle, Procedure and Results