P.S. Moorhead

TL;DR: A consideration of the cause of the eventual degeneration of these strains leads to the hypothesis that non-cumulative external factors are excluded and that the phenomenon is attributable to intrinsic factors which are expressed as senescence at the cellular level.

TL;DR: A combination of cytological and leukocyte culture techniques is described which constitutes a convenient, reliable approach for chromosome studies of humans and yields the following advantages: relative ease of obtaining blood and small volume required.

TL;DR: Ch Chromosomal analysis of metaphases of the human cell line RPMI 2650, derived from a pleural effusion of a patient with neoplasia, show that although its chromosome number is 46 it bears a consistent minor rearrangement involving the D group.