Online Microbiology and Biology Notes
Biochemical Test Notes. Notes on Biochemical Test. Online Biochemical Test related notes. Biochemical Test Notes for undergraduate and graduate students with diagrams.
What does Biuret test for? Proteins are the complex compound formed by thousands of amino acids. Amino acids are amphoteric electrolytes having carboxyl and amino groups that act like acid and base. It has one positive charge and one negative charge, hence these ions are electrically neutral and do not migrate in the electric field. … Read more Biuret Test for Protein
Introduction Carbohydrates are organic molecules that comprise carbon, hydrogen, and oxygen in the ratio (CH2O)n. There are three types of carbohydrates based on their structure and number of carbon atoms present, they are monosaccharides (simple sugar containing 3-7 carbon atoms), disaccharides (comprising of two monosaccharides linked together by the glycosidic bond), polysaccharides (containing eight or … Read more Carbohydrate Fermentation Test | Sugar Fermentation Test
Pyruvate Broth Test Objectives To determine the ability of an organism to utilize pyruvate. It aids in the differentiation between Enterococcus faecalis and Enterococcus faecium. Principle In the identification of microorganisms, the widely used method is the ability of bacteria to form organic compounds by metabolizing certain carbohydrates and related compounds. Pyruvate broth is a carbohydrate-free, … Read more Pyruvate Broth Test
Leucine Amino Peptidase (LAP) Test Objective To detect the presence of the enzyme leucine aminopeptidase for the preliminary characterization of catalase-negative, gram-positive cocci, especially non-beta-hemolytic cocci. Principle of Leucine Amino Peptidase (LAP) Test Leucine aminopeptidase (LAP) test is a rapid test for the detection of enzyme leucine aminopeptidase. In general, Streptococcus pneumoniae and Streptococcus pyogenes, … Read more Leucine Amino Peptidase (LAP) Test
Objectives To determine the ability of the organism to reduce sulfur for the production of hydrogen sulfide. To differentiate members of Enterobacteriaceae, especially the sulfur-reducing Salmonella and Proteus from the non-reducing Morganella morganii and Providencia rettgeri. Principle The Sulfur Reduction Test is performed using the SIM medium. SIM medium also tests for indole production and … Read more Sulfur Reduction Test
Salt Tolerance Test Objectives To determine the ability of an organism to grow in high concentrations of salt. It is used for the differentiation of Enterococci from Non-Enterococci. Principle Salt acts as a selective agent and interferes with membrane permeability and osmotic equilibrium. The salt tolerance medium is a selective and differential medium in which … Read more Salt Tolerance Test
Kligler Iron Agar Test Objective To differentiate the enteric gram-negative bacilli based on the production of hydrogen sulfide and fermentation of dextrose and lactose. Principle Kligler Iron Agar (KIA) test is used in differentiating certain members of the Enterobacteriaceae by demonstrating hydrogen sulfide production and the fermentation of dextrose and lactose. Kligler agar used for … Read more Kligler Iron Agar Test
Potassium hydroxide (KOH) test Objective To visualize the fungal element in the clinical specimens. To examine skin scrapings or flakes and hair for the presence of hyphae and arthroconidia in suspected dermatophyte infections. Principle Potassium hydroxide (KOH) can be used on clinical specimens to clear cellular material and for better visualization of fungal elements. KOH … Read more Potassium hydroxide (KOH) test
Nitrite Reduction Test Objective To determine the ability of an organism to reduce nitrites to gaseous nitrogen or to other compounds containing nitrogen. Principle Nitrate reduction by bacteria is mediated by nitrate reductase and indicates that the organism can use NO3– as an electron acceptor during anaerobic respiration and reduce nitrate to nitrite. Nitrite, on the … Read more Nitrite Reduction Test
Phenylalanine Deaminase Test Objectives of Phenylalanine Deaminase Test To determine the ability of an organism to oxidatively deaminate phenylalanine to phenylpyruvic acid. To differentiate enteric Gram-negative bacilli on the basis of their ability to produce phenylpyruvic acid from phenylalanine. Principle of Phenylalanine Deaminase Test Phenylalanine deaminase medium tests the ability of an organism to produce the enzyme … Read more Phenylalanine Deaminase Test