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The presence of an active β-galactosidase can be detected by X-gal, a colourless analog of lactose that may be cleaved by β-galactosidase to form 5-bromo-4-chloro-indoxyl, which then spontaneously dimerizes and oxidizes to form a bright blue insoluble pigment 5,5'-dibromo-4,4'-dichloro-indigo. This results in a characteristic blue colour in ...
β-Galactosidase (EC 3.2.1.23, beta-gal or β-gal; systematic name β-D-galactoside galactohydrolase) is a glycoside hydrolase enzyme that catalyzes hydrolysis of terminal non-reducing β-D-galactose residues in β-D-galactosides. (This enzyme digests many β-Galactosides, not just lactose.
ortho-Nitrophenyl-β-galactoside (ONPG) is a colorimetric and spectrophotometric substrate for detection of β-galactosidase activity. [1] This compound is normally colorless. However, if β-galactosidase is present, it hydrolyzes the ONPG molecule into galactose and ortho-nitrophen
Galactosidases are enzymes (glycoside hydrolases) that catalyze the hydrolysis of galactosides into monosaccharides.. Galactosides can be classified as either alpha or beta. If the galactoside is classified as an alpha-galactoside, the enzyme is called alpha-galactosidase, and is responsible for catalyzing the hydrolysis of substrates that contain α-galactosidic residues, such as ...
The degree of color development is an indirect measure of the β-galactosidase produced, which itself is directly related to the amount of DNA damage. The Umu Chromotest has the added advantage of having its procedure codified under ISO 13829 "Water Quality- Determination of genotoxicity of water and waste water using the umu-test".
The enzyme beta-galactosidase is a marker for coliforms generally and may be assayed by hydrolysis of enzyme specific glycosides such as o-nitrophenyl-beta-D-galactose. Assays typically include a second sugar linked to a different dye which, when acted on by the enzyme beta-glucuronidase, produces a fluorescent product.
The cloned enzyme donor immunoassay (CEDIA) involves genetically engineering an enzyme (e.g., beta-galactosidase) into two inactive fragments: a small enzyme donor (ED) conjugated with the drug analog, and a larger enzyme acceptor (EA). When the two fragments associate, the full enzyme converts a substrate into a cleaved colored product.
Senescence-associated beta-galactosidase, along with p16 Ink4A, is regarded to be a biomarker of cellular senescence. [ 1 ] [ 2 ] Its existence was proposed in 1995 by Dimri et al. [ 3 ] following the observation that when beta-galactosidase assays were carried out at pH 6.0, only cells in senescence state develop staining.