Use this reagent as supplied, no dilution or further preparation is required. In the presence of peroxidase (HRP, POD), TMB will
be converted to a blue color that can be read at OD650 nm.
If desired, the reaction can be stopped by adding an equal amount of 1 N hydrochloric acid to the reaction volume. This will
yield a yellow color that can be read at OD450 nm.