Some bacteria make substances that other bacteria need to grow. The X factor and the V factor are two such substances. The heat-stable X-factor can be protoporphyrin IX, hemin, or other iron-containing porphyrins. It can be found in red blood cells and outside of them in the blood. The heat-sensitive V-factor may be nicotinamide adenine dinucleotide (NAD) or nicotinamide adenine dinucleotide phosphate (NADP), and it is mostly found inside red blood cells. The X and V factor test or a disc test can be used to find out if a bacterium depends on its X factor or its V factor. The results can help identify the bacteria.
Hopkin’s Cole/Adamkiewicz–Hopkins Test Definition Hopkins Cole Test also referred to as glyoxylic Acid Reaction is among the qualitative testing methods for determining the differences between different types of amino acids and proteins. The test is used to determine the presence of tryptophan, an amino acid, in proteins. Objectives of Hopkin’s Cole Test Principle of Hopkin’s … Read more
Starch Hydrolysis Test Objective Starch Hydrolysis test principle Starch is a polysaccharide that is composed by glucose subunits. The glucose rings may be joined by a 1,4-glucosidic glucosidic link, which results in long, straight chain of glucose. (“1, 4” is a reference to the bond formed between number 1 carbon in one glucose molecule, and … Read more
The MRS formulation was made by de Man, Rogosa, and Sharpe to replace a variable product (tomato juice) and give lactobacilli in general a good place to grow.
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.
What is the Ninhydrin Test? The ninhydrin chemical test is used for determining whether an analyte contains any amines or amino acids. In this test, ninhydrin (a chemical compound with the formula C9H6O4; IUPAC name: 2,2-dihydroxyindane-1,3-dione) is added to a test solution of the analyte. The formation of a deep blue color within the test … Read more
⚠️
Click on your ad blocker icon in your browser's toolbar
Select "Pause" or "Disable" for this website
Refresh the page if it doesn't automatically reload
6 min read 
