VPB 112: General Veterinary Biochemistry (1+1)

SAGAKAUCHI TEST

• This is a very specific test for basic amino acids.

Principle

• Arginine, the only amino acid containing the guanidium group, reacts with α - naphthol in presence of 10% NaOH and Sodium hypochlorite (oxidizing agent), to give a red colored product.
• Non-amino acid compounds containing the guanidine group may also give a positive result.

Procedure

• To 3 ml of the protein solution add 1 ml of 10% NaOH and 1-2 drops of α - naphthol.
• Mix thoroughly and add 4 drops of sodium hypochlorite.
• A red color is formed.
• This indicates the presence of arginine, which contains the guanidine group.