Differential effects of erythrocyte lysates on spectra of potential-sensing carbocyanine dyes.

A recent report by Hladky, S.B. and Rink, T.J. ((1976) J. Physiol. 263, 287--319) demonstrates the binding of a thiocarbocyanine dye (di-S-C3 (5)) to an intracellular constituent from human erythrocytes. Evidence presented below shows that the binding of carbocyanine dyes depends on the particular type of dye used and on the species of erythrocyte from which cellular constituents are prepared. It is recommended that dyes which show minimal binding to intracellular components be used for investigations where carbocyanine dyes are employed as probes of membrane potential.