Online Microbiology Notes

Cetrimide Agar Test- Principle, Procedures, Results, Uses

October 10, 2020 by Anupama Sapkota

Cetrimide Agar Test- Principle, Procedure and Result Interpretation

What is Cetrimide Agar Test? Cetrimide agar test is a biochemical test performed to identify or differentiate Pseudomonas aeruginosa from other microorganisms. The test works on the principle of the ability of an organism to grow in the presence of cetrimide. Cetrimide is a toxic quaternary ammonium detergent that is toxic to most bacteria except for few organisms like P. …

Catalase Test- Principle, Procedure, Types, Results, Uses

October 10, 2020October 10, 2020 by Anupama Sapkota

Catalase Test- Principle, Procedure and Result Interpretation

What is Catalase Test? The catalase test is a biochemical test for aerobic organisms that detects the production of catalase enzyme in the organism. Catalase enzyme is a common enzyme that is found in all living beings that survive in oxygen and catalyzes the decomposition of hydrogen peroxide, releasing water and oxygen. Catalase is an essential enzyme in pathogenic organisms …

Staphylococcus epidermidis- An Overview

October 9, 2020 by Sagar Aryal

What is Staphylococcus epidermidis? Staphylococcus epidermidis is a Gram-positive bacterium belonging to the genus Staphylococcus and is the most frequently isolated species from human epithelia. Staphylococci are known as clustering Gram-positive cocci, nonmotile, non-spore-forming facultatively anaerobic that classified into two main groups, coagulase-positive and coagulase-negative. S. epidermidis belongs to the group of coagulase-negative staphylococci (CoNS), which is different from coagulase-positive …

Genus Spirogyra – An Overview

October 8, 2020 by Anupama Sapkota

Spirogyra Definition Spirogyra is a green alga that is mostly found in freshwater in the form of clumps. These are also called Water silk or Mermaid’s tresses. It is a unicellular organism but can be seen in freshwater bodies as it clumps together to form a multicellular structure. Spirogyra consists of chlorophyll which gives it a green appearance. As a …

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RNA Splicing- definition, process, mechanism, types, errors, uses

October 8, 2020 by Anupama Sapkota

RNA Splicing Definition RNA splicing is a form of RNA processing in which a newly made precursor messenger RNA (mRNA) is transformed into a mature RNA by removing the non-coding sequences termed introns. The process of RNA splicing involves the removal of non-coding sequences or introns and joining of the coding sequences or exons. RNA splicing takes place during or …

DNA Ladders (1 kb, 1 kb plus, 100 bp, 100 bp plus) and Uses

October 8, 2020 by Anupama Sapkota

DNA Ladder Definition DNA ladder is a solution of DNA molecules of different lengths used in agarose or acrylamide gel electrophoresis which is used as a reference to estimate the size of unknown DNA molecules separated on the basis of their mobility in an electrical field through the gel. DNA ladders are essential molecules routinely used in every DNA dealing …

CAMP Test- Principle, Procedure, Types, Results, Uses, Limitations

October 7, 2020 by Anupama Sapkota

CAMP Test- Principle, Procedure and Result Interpretation

What is CAMP Test? CAMP (Christie–Atkins–Munch-Peterson) test is a biochemical test used to differentiate Streptococcus agalactiae from other beta-hemolytic Streptococci. S. agalactiae is the only member of the Group B Streptococci which is separated from other beta-hemolytic Streptococci by the demonstration of a large area of hemolysis when grown with Staphylococcus aureus. This test is used for the presumptive identification …

Butyrate Disk Test- Principle, Procedure, Results, Uses, Limitations

October 7, 2020 by Anupama Sapkota

Butyrate Disk Test- Principle, Procedure and Result Interpretation

What is Butyrate Disk Test? Butyrate disk test is a rapid identification test for the detection of Moraxella catarrhalis on the basis of their ability to utilize bromochloro-indolyl butyrate or 4-methylumbelliferyl butyrate. Moraxella (Branhamella) catarrhalis is now recognized as a major pathogen that causes otitis media, sinusitis, conjunctivitis, bronchitis, and pneumonia. In addition, a large number of M. catarrhalis strains …

Bile Solubility Test- Principle, Procedure, Types, Results, Uses

October 6, 2020 by Anupama Sapkota

Bile Solubility Test- Principle, Procedure and Result Interpretation

What is Bile Solubility Test? Bile solubility test is a biochemical test used for the differentiation and confirmation of Streptococcus pneumoniae from other alpha-hemolytic Streptococci. The bile solubility test has been used as an essential test for the differentiation of S. pneumoniae as it allows the distinction between the two species S. pneumoniae and Streptococcus pseudopneumoniae, which is a challenging task. The …

Bile Esculin Test- Principle, procedure, results, uses, limitations

October 5, 2020 by Anupama Sapkota

What is the Bile Esculin Test? The bile-esculin test is a biochemical test performed to differentiate Enterococci and group D Streptococci from non-group D viridans group Streptococci on the basis of their ability to hydrolyze esculin. Many organisms are capable of hydrolyzing esculin, but only a few of them can do so in the presence of bile (4% bile salts …