Measures of viability in isolated cells

Abstract

Various methods were compared for estimation of cell viability. Cell count, uptake of trypan blue, release of cellular LDH, as well as cell contents of K+ and Na+ were determined in leukocytes, spleen cells, and Ehrlich cells exposed to adverse conditions. After incubation of these cells with NaF, the cell count remained essentially constant; the extent of cell staining and release of LDH increased to a limited level in suspensions of leukocytes and spleen cells and was virtually unchanged in experiments with Ehrlich cells. On the other hand, pretreatment with NaF induced rapid and marked changes in contents of K+ and Na+ in all three cell types. Exposure of the cells to hypertonic conditions caused more pronounced, but similar overall effects. As a consequence of increased tonicity, the cell count decreased and considerable leakage of LDH occurred in all the cells investigated. Whereas the contents of K+ and Na+ in all pretreated cells changed markedly, the cellular uptake of trypan blue was again the least responsive index of cell permeability. The results showed cell staining by trypan blue to be a relatively poor measure of cell viability and suggest use of the ratio cellular K+/Na+ or, even more efficiently, the cell content of K+ as sensitive indicators of plasma membrane integrity.