摘要
Radical substituted proteins are often used as substrates for the determination of protease aetivities, among them azocasein has been widely employed. However, it must be carried out under alkaline condition for colorimetric determination and the colour is not so stable. On studying the reaction of diazo-I-H-tetrazol with protein, we discovered that some metal ions could couple with DHT-casein to form a red-coloured eom-
