Chromosome patterns of human leukocyte established cell lines.

Of 14 lines of human leukocytes, designated LK1D, LK57, LK60, LK63, LK87A, LK91, SK-L1, SK-L3, SK-L4, SK-L5, SK-L6, SK-L7, RPMI 7216, and RPMI 7466, all were classi cally diploid or very near-diploid when first examined. All but one showed occasional No. 10 chromosomes with the near terminal secondary constriction seen in Burkitt lymphoma cells in vitro. Nine lines showed accentuation of secondary con strictions at the usual sites on Chromosomes No. 1 and/or No. 16. Exchanges often occurred at these sites. Some cells in various lines showed multiple secondary constrictions or fragmentation (pulverization), but these and other chromo some abnormalities were in lower incidence than in Burkitt lymphoma strains. Many of the abnormalities in these lines may reflect underlying abnormalities of nucleoli or of nucleolarassociated heterochromatin.