Indole Test- Principle, Reagents, Procedure, Result Interpretation and Limitations

Result Interpretation of Indole Test

This test demonstrate the ability of certain bacteria to decompose the amino acid tryptophane to indole, which accumulates in the medium. Indole production test is important in the identification of Enterobacteria. Most strains of E. coli, P. vulgaris, P. rettgeri, M. morgani and Providencia species break down the amino acid tryptophan with the release of indole. This is performed …

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Oxidase Test- Principle, Uses, Procedure, Types, Result Interpretation, Examples and Limitations

Dry Filter Paper Method

The oxidase test detects the presence of a cytochrome oxidase system that will catalyse the transport of electrons between electron donors in the bacteria and a redox dye- tetramethyl-p-phenylene-diamine. The dye is reduced to deep purple color. This test is used to assist in the identification of Pseudomonas, Neisseria, Alcaligens, Aeromonas, Campylobacter, Vibrio, Brucella and …

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Catalase Test- Principle, Uses, Procedure, Result Interpretation with Precautions

Result Interpretation of Catalase Test and Examples

This test demonstrate the presence of catalase, an enzyme that catalyses the release of oxygen from hydrogen peroxide (H2O2). It is used to differentiate those bacteria that produces an enzyme catalase, such as staphylococci, from non-catalase producing bacteria such as streptococci. Normally 3% H2O2 is used for the routine culture while 15% H2O2 is used …

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Coagulase Test- Principle, Procedure, Types, Interpretation and Examples

Introduction to Coagulase Test Coagulase test is used to differentiate Staphylococcus aureus (positive) which produce the enzyme coagulase, from S. epidermis and S. saprophyticus (negative) which do not produce coagulase. i.e Coagulase Negative Staphylococcus (CONS). Principle of Coagulase Test Coagulase is an enzyme-like protein and causes plasma to clot by converting fibrinogen to fibrin. Staphylococcus aureus produces two forms …

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