LAUSR

A simple and practical method for detecting and measuring the protease activity of unknown samples was developed. The method included preparing a piece of capillary-tubing-sheathed proteinaceous gel, dipping the gel into solutions of test substances and measuring the truncation length of the gel tip. The existence of protease and its activity were indicated and quantitated by the truncation length which was found to be proportionately relevant to protease activity (as V8 protease, R2 = 0.9835). The proteinaceous gel was both thermally and chemically stable, hydrolyzable by nine types of proteases, and showed reliable results for samples from soil, beach mud, fruit, and municipal water. The present method showed a potential use for field study.