Effects of different fixative solutions on labeling of concanavalin-A receptor sites in human T-lymphocytes.

We have studied the effect of several fixative solutions on the number of Concanavalin-A (Con-A) receptor sites of human peripheral blood T-lymphocytes. Cells treated with different fixative solutions (glutaraldehyde (G); formaldehyde (F) G+F; osmium tetroxide (Os); Os+G; Os+F; and Os+G+F) were labeled with a Con-A gold labeled horseradish peroxidase (HRP) complex and the number of gold particles on the lymphocytic surface was evaluated. Comparison of cells treated with the different fixatives used showed significant differences in the density of labeling. After G fixation the number of gold particles was lower than after fixation with Os or F. Moreover, G used in combination with F or Os reduced the labeling obtained when the two latter fixatives were used alone.