Erythrosin and pH gradient induced photo-voltages in bilayer membranes

Erythrosin and light flashes induce voltage transients across bilayer membranes in the presence of transmembrane pH gradients. Fast voltage transients, which rise in less than 50 nsec and fall in approximately 500 nsec, are attributed to photo-deprotonation of dye sorbed in the glycerol region of phospholipid membranes. Six other halogenated xanthene dyes induce similar effects, which apparently resulted from triplet states of monoanionic dye. No photo-effects were observed with fluorescein.