Nelson-Somogyi method is a classical colorimetric method used for quantitative estimation of reducing sugars like glucose in biological and industrial samples. It is a two step redox based assay where reducing sugars act as reducing agent and reaction is carried out in alkaline condition. In first step, sample containing reducing sugar is heated with alkaline
Peroxide Value (PV) Test is a chemical titration used to find the peroxides and hydroperoxides present in fats and oils. It is taken as an early index of oxidation and shows the freshness, quality, and keeping life of the sample. A high value means the oil is turning rancid. Objectives of Peroxide Value Test Principle
Ninhydrin Test is a chemical test used to detect ammonia, primary amines, secondary amines and α-amino acids in a given sample. It is done by treating the sample with ninhydrin (2,2-dihydroxyindane-1,3-dione). The reagent acts as a strong oxidizing agent and the reaction is seen after heating. During this test, amino acids undergo oxidative deamination and
The novobiocin (antibiotic) differentiation disc can be used in the Novobiocin Susceptibility Test to help make a preliminary distinction between Staphylococcus saprophyticus and other coagulase-negative staphylococci (CoNS) in clinical (urinary) specimens.
OF (Oxidation-Fermentation) test is a biochemical test used to find out how a bacterium utilize carbohydrate (mainly glucose). It was developed by Hugh and Leifson (1953). It differentiates organisms into fermentative type and oxidative type based on acid production in anaerobic and aerobic condition. It is done in a semi-solid OF medium having high carbohydrate
Pyruvate Broth Test is a biochemical test used to determine the ability of a bacterium to utilize pyruvate as a carbon and energy source. It is done in a carbohydrate-free broth medium containing sodium pyruvate. The medium contains an indicator (bromothymol blue) which gives greenish-blue colour initially. If the organism metabolizes pyruvate, organic acids are
Phenylalanine Deaminase Test (PDA test) is a biochemical test used to detect the enzyme phenylalanine deaminase produced by some bacteria. It is used to identify and differentiate gram-negative enteric bacteria, mainly the Proteeae group from other Enterobacteriaceae. In this test, the organism is grown on a medium containing phenylalanine. If the enzyme is present, phenylalanine
The Bacitracin susceptibility test is one of the antimicrobial disc tests used to distinguish between group A and other -hemolytic Streptococci.
Streptococcus pneumoniae can be distinguished from other viridans streptococci by showing that it is sensitive to optochin, dissolves in bile, reacts with a specific DNA probe, or has species-specific capsular polysaccharides.
The SXT (sulfamethoxazole-trimethoprim) susceptibility test tells the difference between group A and B streptococci and other hemolytic streptococci.
