Biochemical Test Notes | Microbe Notes

Urease Test- Principle, Media, Procedure, Result, Uses

October 23, 2020 by Anupama Sapkota

Urease Test- Principle, Procedure and Result

Urease Test Definition Urease test is a biochemical test that detects the alkaline fermentation of urine (urea) with the resultant production of ammonia by microorganisms. The fermentation of urea occurs in the presence of the enzyme ‘urease’, resulting in two molecules of ammonia and carbon dioxide. Urease activity is one of the important characteristics for the identification of Proteus species …

Indole Test- Principle, Media, Procedure, Types, Results, Uses

October 23, 2020 by Anupama Sapkota

Indole Test Definition Indole test is a biochemical test conducted on bacterial species to detect their ability to produce indole from tryptophan in the presence of a group of enzymes called ‘tryptophanase’. It is a qualitative test that tests the conversion of tryptophan into indole. The test is performed as a part of the IMViC test that is used to …

Hippurate Hydrolysis Test- Principle, Procedure, Result, Uses

October 23, 2020October 23, 2020 by Anupama Sapkota

Result Interpretation of Hippurate Hydrolysis Test

Hippurate Hydrolysis Test Definition Hippurate hydrolysis test is a biochemical test that differentiates microorganisms on the basis of their ability to hydrolyze hippurate into glycine and benzoic acid by the enzymatic action of hippuricase. Traditionally, the test was performed using a ferric chloride indicator to detect benzoic acid, which would take a longer period of time. Nowadays, however, the test …

Growth at 42°C Test- Principle, Procedure, Result, Uses

October 23, 2020October 23, 2020 by Anupama Sapkota

Growth at 42°C Test- Principle, Procedure and Result Interpretation

What is Growth at 42°C Test? The growth at 42°C test is a presumptive identification test used to differentiate between the species of the fluorescent pseudomonas group as well as other non-fermentative bacteria. The test is based on the ability of an organism to grow at 42°C, which allows the differentiation of Pseudomonas aeruginosa from the other fluorescent pseudomonads. Temperature …

Gelatin Hydrolysis Test- Principle, Procedure, Types, Result, Uses

October 23, 2020October 23, 2020 by Anupama Sapkota

Gelatin Hydrolysis Test- Principle, Procedure and Result Interpretation

Gelatin Hydrolysis Test Definition Gelatin hydrolysis test is a biochemical test performed as a presumptive test for the identification of Staphylococcus, Enterococcus, and other Gram-positive bacilli. Gelatin hydrolysis test is also termed as the Gelatin Liquefaction test as it involves the liquefaction of gelatin in the presence of the gelatinase enzyme. Gelatinase is an important enzyme in various pathogenic organisms …

Esculin Hydrolysis Test- Principle, Procedure, Results, Uses

October 23, 2020October 23, 2020 by Anupama Sapkota

Esculin Hydrolysis Test- Principle, Procedure and Result Interpretation

What is the Esculin Hydrolysis Test? Esculin hydrolysis is a useful test in the differentiation of both gram-positive and gram-negative bacteria covering a broad spectrum of aerobes, facultative anaerobes, and anaerobes. Esculin hydrolysis is utilized as a taxonomic tool in the identification of a wide variety of microorganisms, including the family Enterobacteriaceae, genera Streptococcus and Listeria, non-fermentative gram-negative bacilli, and …

Lipase Test- Objectives, Principle, Procedures, Results, Uses

October 23, 2020October 22, 2020 by Sagar Aryal

Objectives of Lipase Test The objective is to identify bacteria capable of producing the exoenzyme lipase. The Lipase Test is used to detect and enumerate lipolytic bacteria, especially in high-fat dairy products. A variety of other lipid substrates, including corn oil, olive oil, and soybean oil, are used to detect differential characteristics among members of Enterobacteriaceae, Clostridium, Staphylococcus, and Neisseria. Several …

Deoxyribonuclease (DNase) Test- Principle, Procedure, Result, Uses

October 22, 2020October 22, 2020 by Anupama Sapkota

DNase Test Agar- Principle, Procedure and Result Interpretation

Deoxyribonuclease (DNase) Test Definition Deoxyribonuclease (DNase) Test is a biochemical test performed to differentiate organisms on the basis of their ability to produce the DNase enzyme. Deoxyribonucleic acid (DNA) is a large molecular-sized polymer composed of multiple nucleotides monomer that is large in size and thus, cannot enter the bacterial cell membrane. Microorganisms produce the deoxyribonuclease enzyme to breakdown the …

Optochin Susceptibility Test- Principle, Procedure and Results

October 23, 2020October 21, 2020 by Sagar Aryal

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 adenosine triphosphate (ATP) in microorganisms. Optochin is …

Novobiocin Susceptibility Test- Principle, Procedure, Results, Uses

October 23, 2020October 21, 2020 by Sagar Aryal

Result Interpretation of Novobiocin Susceptibility Test

Objectives of Novobiocin Susceptibility Test To determine the susceptibility pattern of a 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 of S. …