IL STUDIES ON THE ISOLATION AND CHARACTER- IZATION OF HUMAN MINI SEGREGANT CELLS

SUMMARY A method is described for the isolation, according to size, of mini segregants produced by the abnormal cleavage of reversibly arrested mitotic HeLa cells. Many of these mini segregants contain small amounts of DNA, as judged by Feulgen staining and chromosome analysis. After fusion with mitotic HeLa cells, the interphase chromosomes of the mini segregants are seen as either monovalent or bivalent prematurely condensed chromosomes (PCC), some of which are damaged. A proportion of isolated mini segregants synthesize DNA, RNA and protein. Fusion of mini segregants with interphase HeLa cells gives rise to cells with 'hybrid' karyotypes.