Substrati cromogenici

N-(3-Sulfopropyl)-3,3',5,5'-tetramethylbenzidine (TMB) sodium salt is a highly sensitive chromogenic substrate used for the detection and quantification of peroxidase enzyme activity. This water-soluble substrate undergoes a color change from colorless to blue upon oxidation by peroxidase enzymes in the presence of hydrogen peroxide. The reaction can be stopped by adding an acid, resulting in a yellow color that can be measured spectrophotometrically. TMB sodium salt is widely used in various applications, including enzyme-linked immunosorbent assays (ELISA), immunohistochemistry, and other diagnostic tests, due to its high sensitivity, low background signal, and excellent stability.

3,3'-Diaminobenzidine (DAB) is an organic compound derived from benzidine. DAB is water-soluble as the tetrahydrochloride salt and is used in immunohistochemical staining of nucleic acids and proteins. Within research in Alzheimer's disease, Aβ protein amyloid plaques are targeted by a primary antibody, and subsequently by a secondary antibody, which is conjugated with a peroxidase enzyme. This will bind DAB as a substrate and oxidize it, producing an easily observable brown colour. 3,3’-Diaminobenzidine tetrahydrochloride hydrate is also available as the tetrahydrochloride salt and as the free base.

4-Nitrophenyl 2-acetamido-3-O-[2-O-a-L-fucopyranosyl-b-D-galactopyranosyl)-2-deoxyb-D-galactopyranoside is a water soluble, fluorescent probe that can be used for detecting the presence of β-(1→4) -linked galactosaminoglycans. The dye is a substrate for enzymes such as α--mannosidase, β--glucuronidase and β--galactosidase. The dye is also an excellent ligand for lectins such as concanavalin A and wheat germ agglutinin. This product is a diagnostic reagent that has been shown to have high purity and quality. It has CAS No. 93496-53-8 and can be used in food testing, bioluminescence, environmental testing, or high purity applications.

Aldol® 514 inositol-phosphate is a chromogenic enzyme substrate used for detection of phosphatidylinositol specific phospholipase C (PI-PLC, EC 4.6.1.13). The colorless enzyme substrate is cleaved by PI-PLC positive microorganisms, yielding a red-orange color. The substrate thus enables the detection and identification of various bacteria, such as, pathogenic strains of Listeria, Clostridium, Bacillus, and Staphylococcus. Aldol® 514 inositol-phosphate is suitable for use under aerobic and anaerobic conditions.

5-Bromo-4-chloro-3-indoxyl butyrate is a colorimetric substrate used to detect and quantify esterase activity. Upon hydrolysis by esterases, it yields a blue-green dye, allowing the detection and quantification of enzyme activity. It is commonly used in assays for the screening of esterase-producing microorganisms and in research aimed at understanding the role of esterases in various cellular processes.