Various biochemical and biophysical properties of a subpopulation of rat thymocytes isolated in a Ficoll gradient
Zherbin, E.A.; Khanson, K.P.; Vashchenko, V.I.; Reshchikov, A.M.; Sungurov, A.I.
Biulleten' Eksperimental'noi Biologii i Meditsiny 91(10): 434-436
1981
ISSN/ISBN: 0365-9615 PMID: 6976191 Document Number: 174044
Subpopulations of rat thymocytes were obtained by cell precipitation in a single-stage transient phycoll gradient (isorapid precipitation). The fraction obtained were characterized in terms of the size, intensity of UV fluorescence, protein content and nucleoid mobility. The radius of thymocytes and UV fluorescence intensity monotonously increased during the transfer from the upper to lower fractions. The cells of medium-size fractions were characterized by the minimum content of cytoproteins and maximum mobility of nucleoid. In order to evaluate the density of thymocytes in the fractions, use was made of an additional cell precipitation in the phycoll-paque stage rho = 1.077. Incubation of thymocytes in medium 199 with a 10% rat serum led to the increased cell density in all the fractions, particularly in medium-size ones. Gamma-irradiation of thymocytes in a dose of 5 Gy appreciably accelerated the process under consideration. It is assumed that the medium-size fractions are enriched with thymocytes in G1 S phase, while lower fractions in G2 phase of the mitotic cycle. At the same time the fractions obtained appear to contain the subpopulations of thymocytes undergoing different stages of differentiation.