OPD, Ortho-Phenylenediamine, is used as a chromogen substrate in ELISA procedures with an absorption maximum at 492 nm and produces a yellow colour during the enzymatic degradation of hydrogen peroxide by horseradish peroxidase. After addition of sulfuric acid you will obtain a very stable end solution. The fizzing, buffer containing tablets are dissolved in distilled water within few minutes.
This will give solution of pH 5.2 + 0.1. You here get the maximum convenience,- an easy, safe and reliable way to operate.
Stability life time is 18 months at 4°C.