[Separation of a rat thymocyte population in a ficoll-paque gradient. III. The optical characteristics of the fractions].

Values of the own ultraviolet fluorescence (UVF) intensity, of the relative UVF intensity (i/R2 proportion, where i--UVF-intensity, R--cell radius), of optical densities of cell suspensions beyond their light absorption band as well as of rates of light scattering by cells at the 90 degrees angle to the beam direction were determined for rat thymocyte fractions obtained by sedimentation of the total thymocyte population on the Ficoll-Paque layer (rho=1.077). It has been shown that the upper (less dense) thymic fractions have the greatest values of parameters assayed when compared with the bottom cells. Interrelations of the data obtained with those on the cell sizes, cytoprotein contents and internal cellular structure are discussed.