Diffusibility of Dyes in Buffered and Unbuffered Solutions. ∗

Abstract

Summary

The rate of diffusion of basic dyes depends not only on the concentration gradient but also the medium. The diffusion of dyes into a concentrated buffer is faster than into a diluted one. The concentrated buffer represses the ionization, and thus retards the back diffusion. If the buffer compartment is diluted in the same proportion as the dye compartment, the rate of diffusion of the dyes is only slightly affected, if at all, by a 4-fold dilution. In diffusion studies with Methylene Blue it was found that brane has, in different media, a different diffusion capacity. This work suggests that conclusions based on diffusion measurements made on simple aqueous solutions may not be equally valid for biological systems.