Cytogenetic, growth rate and virus susceptibility differences in sublines of H. Ep. 2 cells.

Two sublines of H. Ep. 2, obtained from New Haven (NH) and Sao Paulo (SP) respectively, were studied in relation to their morphology, growth rate, virus susceptibility and chromosomes. The Sao Paulo subline was divided into two, one cultivated in Hanks lactalbumin medium plus 20% of calf serum and the other in modified Eagle's medium, to investigate the possible influence of the medium of cultivation on these variables. This influence proved to be small. But significant differences were observed between the two sublines, H. Ep. 2 NH showing a lowered rate of growth, less susceptibility to virus infections and a higher modal chromosome number. The changes in chromosome number were of such a nature that there was practically no overlapping in the range of variation in the two sublines. Groups B, D and F were the most affected.