Abstract
Department of Anatomy and Physiology, University of Dundee Peter J. Stoward Many enzymes diffuse out of sections of unfixed tissue when they are incubated in conventional aqueous media. This invalidates their quantitative assay by microdensitometry. The quantitative effectiveness of three methods for overcoming this problem are reviewed. The methods utilise semipermeable membranes, polyvinyl alcohol-containing media, and agarose gel films. Unfortunately, most applications of these techniques reported to date have given data that do not meet criteria of validity. A new approach based on the gel film technique for the kinetic analysis of a soluble enzyme in situ by computer-assisted image analysis is described in detail.
