Ploidy of Living Clones of Human Somatic Cells Determined by Mensuration at Metaphase

Tetraploid clones have been useful for studies of somatic segregation (10), mutation (4), and the regulation of protein synthesis (14, 13, 12) . With the availability of various heterochromatin markers, such material is also proving valuable for cytological studies of interphase (5) . Finally, clones of cells with various ploidies should serve as very precise and convenient standards for flow microfluorometric assays of cell DNA (8, 1) . We report here a rapid and simple technique for the diagnosis of ploidy in clones of somatic cells derived from human skin and amniotic fluid. The method employs objective measurements on small samples of living cells. Other methods, such as karyotyping and chemical assays, take much longer and require sacrifice of all or part of the cultures .