Stable Chromosome Changes in a Human Malignant Melanoma¹ Free

A cell culture was established from a human malignant melanoma. Karyotype analyses using some of the newer staining techniques revealed a modal chromosome number of 45 with the presence of a ring, a large marker chromosome with an interstitial C-band, and at least five other structural rearrangements resulting in marker chromosomes. Most of these changes occurred in vivo since they were identifiable in the biopsy material 4 hr after the culture was initiated. They persisted in early and later subcultures. Although the culture grew slowly, the ring remained relatively stable while endoreduplication decreased and 2S stem cells increased with time.