Selection of mitotic Chinese hamster ovary cells from microcarriers

We describe a method of collecting large quantities of mitotic cells from a population of Chinese hamster ovary cells which were exponentially growing on positively charged dextran microcarriers in suspension culture. These cells were treated for 2.5 h with colcemid, and mitotic cells were harvested from the oicrocarriers by increasing spinner velocity. A yield of 2–3% of the total population was obtained using this method; of the cells collected, 85–95% were in metaphase as determined by microscopic inspection. Both synchrony and cell viability were excellent in the selected population.