A new sensitive fluorometric method for measurement of plasma exudation in the inflammatory skin reaction.

A new fluorometric method using fluorescein isothiocyanate-conjugated bovine serum albumin (F-BSA) as a tracer has been developed for measurement of vascular permeability in the skin tissues of rats. This simple and rapid assay has the advantage of high sensitivity, good recovery, and low cost. The tracer extravasated in the skin was recovered as fragments of F-BSA by digestion of the tissue in caustic alkali. The recovery rate of the fluorescence intensity of the tracer from the skin was about 98%. The time required for the extraction of the fluorescent tracer from the skin sample was only 2 hr.