Abstract
In order to obtain large quantities of metaphase chromosomes, we have established the optimum conditions for obtaining a large mitotic cell population from cultured Chinese hamster Don cells (CH-Don-13 clone) by two treatments with a combination of colcemid and harvesting techniques: after pretreatment of a given number of CH-Don-13 cells with 0.025μg/ml of colcemid for 6 hours, the first mitotic cell population was collected by harvesting and the remaining cell population was again treated with 0.025 μg/ml of colcemid for 4 hours; then the second mitotic cell population was collected by harvesting and combined with the first mitotic cell population kept at 0° to 4°C. Mitotic cells obtained by this method showed no significant biological or cytological damage, and the chromosomes isolated from these cell populations were morphologically intact.
