1. What is diphenylamine reagent ?

Diphenylamine reagent is an organic compound with the formula (C₆H₅)₂NH belonging to the class of aromatic amines. The compound exists as a colourless solid at ordinary room temperature, but samples are often yellow due to oxidized impurities. Diphenylamine reagent is used as a pre- or postharvest scald inhibitor for apples. It can protect the apple skin from the oxidation products of alpha-farnesene during storage, and it can distinguish RNA from DNA.

2. The diphenylamine method to distinguish RNA from DNA

It is known that diphenylamine under conditions of the Dische test may react with certain sugars when present at high concentrations. This is the basis diphenylamine method for fructose and inulin determination. The diphenylamine reagent is usually applied to partially purified material (acid precipitated) from which interfering substances are removed. Through the aiphenylamine reaction, it can distinguish RNA from DNA. The reaction depends on the conversion of the pentose to w-hydroxylaevulinic aldehyde which then reacts with diphenylamine to give a a blue colored complex. The intensity of the blue color is proportional to the concentration of DNA.

Therefore, we should use the diphenylamine indicator solution completely. At the same time, the company of Hangzhou Chemfar Ltd., which has more than 20 years' experience focused on providing integrated development and manufacturing service to the pharmaceutical and fine chemical industry, showed that diphenylamine was of great importance in many experiments pointed that we should improve the application of diphenylamine reaction in the identification of DNA and RNA.