Micromethod for chromosome preparations from Chinese hamster lymphocytes

Chromosome preparations from Chinese hamster lymphocytes were made by culturing for 2 to 6 days 50,000 to 800,000 lymphocytes in flat-bottomed Cooke microtiter plates in 0.1 or 0.2 ml Roswell Park Memorial Institute-1640 medium (RPMI-1640) supplemented with 5--40 microliters PHA/ml, 20% fetal calf serum (FCS), and 40 microns 2-mercaptoethanol. Depending on blood volume and cell concentrations used, it was possible to obtain up to 1400 well-spread metaphases from one venepuncture.