Biochemical tests are laboratory procedures that use specific chemical reactions to identify and characterize microorganisms, such as bacteria. These tests are often used to identify the presence of specific enzymes or metabolic pathways in a microorganism, which can help to distinguish it from other microorganisms.
Some common biochemical tests used in bacteriology include:
Oxidase test: This test is used to detect the presence of the enzyme cytochrome oxidase, which is involved in the metabolism of oxygen. Catalase test: This test is used to detect the presence of the enzyme catalase, which helps to break down hydrogen peroxide. Indole test: This test is used to detect the presence of the enzyme tryptophanase, which breaks down the amino acid tryptophan. Nitrate reduction test: This test is used to detect the ability of a microorganism to reduce nitrate to nitrite. Gelatinase test: This test is used to detect the ability of a microorganism to produce the enzyme gelatinase, which breaks down gelatin.
These are just a few examples of the many different biochemical tests that are used in bacteriology. Biochemical tests can be useful for identifying and classifying bacteria, and for understanding their metabolism and ecological role.
The bulk of plasma proteins are composed of big particles, making it difficult for them to pass through the glomeruli of the kidney. However, kidney tubules filter out and reabsorb smaller protein particles back into the blood. There are traces of proteins such as Tamm-Horsfall protein, hormones, mucopolysaccharides, albumin, enzymes, and immunoglobulins in normal urine. … Read more
The majority of plasma proteins are too big to pass through the kidney’s glomeruli. The limited quantity of protein that does filter through is often reabsorbed by the renal tubules back into the blood. Normal urine contains only trace levels of protein (less than 150 mg per 24 hours). Tamm-horsfall protein (up to 40%), albumin … Read more
What is Pauly’s Test? Purposes of Pauly’s Test Principle of Pauly’s Test The presence of tyrosine and histidine can be determined with this test with high sensitivity. Sulphanilic acid is dissolved in hydrochloric acid and used as the reagent in this test. When being exposed to sodium nitrite and hydrochloric acid, sulphanilic acid forms a … Read more
Many bacteria produce a group of enzymes known as beta-lactamases that are mediated through genes in plasmids or the chromosomes. Beta-lactamase can be a constant process or it may be triggered through contact with antimicrobials. Beta-lactamases hydrolyze (and consequently inhibit) the beta-lactam ring of many Cephalosporins as well as penicillins. Beta-Lactamase Test is a rapid test to determine the presence of beta-lactamase , an enzyme that is produced by the strains from Staphylococcus aureus Neisseria gonorrhoeae, Branhamella catarrhalis as well as Haemophilus influenzae.
Principle of PYR Test Purpose of PYR Test Procedure of PYR Test The PYR examination is accessible in many versions. The original PYR test took 16 to 20 hours, but a 4-hour broth assay is now available, as reported in this post. Other forms include quick (10-15 minute) assays in which organisms to be evaluated … Read more
What is Urease Test? Purpose of Urease Test Principle of Urease Test (NH2)2CO + H2O → CO2 + 2NH3 Media Used for Urease Test Two types of media are typically employed to detect urease activity. Christensen’s urea agar is employed to identify urease activity in numerous bacteria. Stuart’s urea broth is largely used to distinguish … Read more
Principle of Nitrite Reduction Test Nitrites combine with an acidic solution of sulfanilic acid and alpha-naphthylamine to produce a red azo dye. In each test reaction, the appearance of the red dye shows the presence of NO2- in the test tube, either as an unreduced main substrate, a product of the test organism’s reduction of … Read more
Test Name Esculin Hydrolysis test Purpose This test is used to try to figure out what kind of Enterobacteriaceae it is and how it differs from other kinds.To see if the microbe can use esculin as a source of carbon by breaking it down with water. Media Required Esculin Hydrolysis Agar Result Positive: Blackened medium, … Read more
Purpose of Gram-Sure Test Principle of Gram-Sure Gram-negative organisms’ cell walls include aminopeptidase, which can be identified through the hydrolysis of L-alanine-7-amido-4-methylcoumarin, a nonfluorescent substrate, into a fluorescent product. Materials Required Quality Control All Gram-Sure lot numbers were tested with the following quality control organisms and determined to be acceptable. The examination of control organisms … Read more
Test Name Deoxyribonuclease (DNase) Test Detection DNases enzyme Uses To find out if an organism can break down DNA and use it to get carbon and energy so it can grow.To distinguish Staphylococcus aureus from other Staphylococci. Result DNase Test Agar: After adding 1N HCl, a clear zone forms around the growth line, but the … Read more
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