Blue. Under the condition of boiling water bath, the reaction of DNA with diphenylamine was blue. Therefore, diphenylamine can be used as a reagent for DNA identification.

usage method

1. Prepare diphenylamine reagent, take 0.1mlb solution, drop into 10mla solution, and mix well.

2. Identification: put 4ml DNA extract into the test tube, add 4ml diphenylamine reagent, and observe the color of the solution (unchanged blue) after mixing.

And heated with a boiling water bath. During the heating process, always pay attention to the color change of the solution in the test tube (light blue gradually appears).

3. Cooling observation after heating.

When DNA is heated under acidic conditions, the glycosidic bond between purine base and deoxyribose breaks to generate purine base, deoxyribose and deoxypyrimidine nucleotide, while 2-deoxyribose is generated by heating and dehydration in acidic environment ω- Hydroxyl- γ- Keto valeraldehyde reacts with diphenylamine reagent to form a blue substance.

Purpose:

1. It is used for preparing azo dyes and other dyes, and also as a stabilizer of nitrocellulose.

2. Used as polymerization inhibitor and polymerization inhibitor for free radicals. This product is a mixed component of azo dyes such as acid yellow G and acid orange IV. it is also used in the production of rubber accelerator, antioxidant, plastic stabilizer and veterinary drug sulfurized diphenylamine.

3. Used for colorimetric determination of nitrate, nitrite, chlorate and magnesium. It is used as redox indicator, oxide test or determination, organic synthesis and liquid desiccant.