What is the assay for enzyme activity that can be read in visible range?
There are some methods detecting reduced end after enzyme reaction. SKK engineering division uses 3.5 Dinitrosalicyclic acid after enzyme reaction, boil for 5 minutes then OD, at 545 mm. But this is very poor in sensitivity and is not suitable for quantitative assay. They only use it as qualitative method to see if enzyme exists or not. Scientists may know other procedures detecting reducing end of the reactant.
