In vitro transformation of Chinese hamster lung cell line.

Karyotypical changes in connection with spontaneous in vitro transformation of primary Chinese hamster lung cultures were followed. At the 26th passage the cultures were spontaneously transformed to an established cell line in the near-diploid range (CHAL-cells). The only chromosomal change which could be observed in the stemline of CHAL-cultures after R-banding and karyotyping was the presence of an extra chromosome giving the following karyotype, 23, XY, +mar. The distal part of the marker showed banding patterns corresponding to 3q21-3qter.