1. For kinetic or non-stopped ELISA assays, the TMB chromogen has maximal Absorbances at 370nm and 652nm.

2. N,N-Dialkylanilines react with 5-nitroisatin chloride to give a bluegreen chromogen with a characteristic absorption spectrum.

3. Tampering with the principal image causes chromogen to react with the electron-acceptor color developer material to provide a color indication of tampering.

4. The principle of chemical tests to detect occult blood is based on the fact that hemoglobin and its derivatives react in a similar way to peroxidase enzymes– by catalyzing the transfer of an oxygen atom from the peroxide to a chromogen such as Benzidine, o-toludine, guaiac or aminophenazone.Oxidation of the chromogen is indicated by the production of a blue, blue-green or …