Flow cytometric analysis of DNA content for ploidy determination in human solid tumors

Flow cytometric studies of cellular DNA content were conducted in 26 patients with a variety of neoplasms. Cell dispersal was achieved with pepsin treatment, and a combination of ethidium bromide and mithramycin was used as DNA specific staining procedure. All measurements were conducted with a new sheath flow chamber in a PHYWE ICP 11 pulse cytophotometer. All but one patient with multiple myeloma had unimodal tumor cell DNA distributions. With human granulocytes as reference standard, 24 of 26 tumors were aneuploid; and of these, 23 showed varying degrees of hyperdiploidy. Except for one patient, ploidy abnormalities were stable on repeat examination.