Diffusion of bovine serum albumin in a neutral polymer solution.

The diffusion coefficient D of bovine serum albumin through various solutions (pH 7.0, 0.5M NaCl) of polyethylene oxide ( M , 1 x lo5, 3 x lo5) was studied with quasielastic light scattering. In solutions of the 1 x lo5 polymer solution a t polymer concentrations above 0.5 g/L, D is considerably greater than would have been expected from the viscosity of water:polymer mixtures, the deviations being larger at low protein concentration than a t high protein concentration. With either polymer, D falls with increasing protein concentration.