PYR test (Pyrrolidonyl Arylamidase test) is a rapid colorimetric biochemical test used in clinical microbiology. It is done for detection of enzyme pyrrolidonyl arylamidase (pyrrolidonyl aminopeptidase) in bacteria. In this test the bacteria is exposed to a synthetic substrate L-pyrrolidonyl-β-naphthylamide. If the enzyme is present the substrate is hydrolyzed and β-naphthylamine is released which is … Read more
Urease test is a biochemical assay used in microbiology to detect whether microorganism produces urease enzyme or not. It is the process in which urea is broken down into ammonia and carbon dioxide by urease enzyme. When urease producing organism is inoculated in urease broth or agar the ammonia is rapidly accumulated and pH is … Read more
Nitrite Reduction Test is a biochemical test, which is used to determine that bacteria can reduce nitrite (NO2−) into other nitrogenous compounds. The nitrite is further reduced to nitric oxide (NO), nitrous oxide (N2O), nitrogen gas (N2) or ammonia (NH3). This test mainly indicates the ability of organism to remove nitrite from medium. In this … Read more
It is a rapid and simple test used for the determination of microbiological quality of milk. It is commonly employed in dairy laboratories to estimate the bacterial load present in milk samples. The test is based on the principle that actively growing bacteria utilize dissolved oxygen during their metabolic activities. Due to this oxygen consumption … Read more
Cetrimide Selective Agar is a solid medium that is recommended for use in qualitative procedures for selective isolation and presumed identification of Pseudomonas aeruginosa and other nonfermenting, gram-negative bacilli.
The Butyrate Disk Test is a rapid biochemical test used in microbiology laboratory for the detection of enzyme butyrate esterase in bacteria. It is mainly used for the presumptive identification of Moraxella catarrhalis, which is an important human pathogen associated with respiratory tract infections. It is useful because this organism shows morphological similarity with Neisseria … Read more
The DNase test is a differential biochemical test which is used to detect the ability of microorganism to produce an extracellular enzyme called deoxyribonuclease (DNase). It is the process where polymerized DNA present in the medium is hydrolyzed into smaller nucleotide fragments by the action of this enzyme. These degraded products can be absorbed by … Read more
It is a biochemical test used for the identification and differentiation of non-fermentative Gram-negative bacteria. It is mainly applied for the confirmation of Pseudomonas aeruginosa. This test is based on the ability of the organism to utilize acetamide as the sole source of carbon and nitrogen. The test medium contains acetamide and a pH indicator … Read more
The Casein Hydrolysis Test is a biochemical test that is used to determine the ability of microorganism to produce and secrete extracellular proteolytic enzyme known as caseinase. It is the process in which casein protein of milk is broken down into smaller soluble products. Casein is the main protein present in milk and it is … Read more
Gram-Sure Test is a rapid qualitative diagnostic test used for the differentiation of aerobic Gram-negative and Gram-positive bacteria. It is mainly applied for bacteria that are rods or coccobacilli in shape. This test works by detecting the presence of a specific enzyme known as L-alanine aminopeptidase. This enzyme is present almost exclusively in Gram-negative bacterial … Read more
