Comparison of Several Methods for Isolation of Rat Peritoneal Mast Cells.

Several dense media were compared for suitability for isolation of rat peritoneal mast cells. Mast cells isolated in 35% Ficoll (a synthetic polysaccharide) or in 37% bovine serum albumin solutions did not lose histamine during the isolation procedure or during a short period of incubation in an isosmotic medium. They responded normally to the histamine releasing action of compound 48/80 or antigen. In contrast, cells isolated in three types of sucrose media lost much of their histamine during isolation and during subsequent incubation in an isotonic medium. Histamine release induced by compound 48/80 or antigen was less than in mixed peritoneal cell suspensions. It is concluded that concentrated sucrose solutions damage mast cells, probably as a result of the hypertonicity of the media.