Translational diffusion was studied by the classical method of forming a boundary between the solution and the solvent on Tsvetkov polarizing diffusiometer (Tsvetkov 1989). The diffusion boundary was formed in glass cell of length h = 30 mm along the beam path. The optical system used for recording the solution-solvent boundary in diffusion analysis was a Lebedev’s polarizing interferometer (Lebedev 1930). Translational diffusion coefficients were calculated from the equation: 1 where σ2 is the dispersion of the diffusion boundary calculated from the maximum ordinate and the area under the diffusion curve, σ02 is the zero dispersion characterizing the quality of boundary formation, and t is the diffusion time. Experiments were carried out at 25°C, and the intrinsic diffusion coefficient, which depends only on the macromolecule properties, is calculated as: [D] = D 0η0/T.