L-Cells in Mitosis Selected by an Improved Technique

A selection method was developed using a specially designed culture flask that increased the yield of synchronous L-cells. As many as 1.5 × 106 cells of which 90 % were in mitosis were obtained after five cell harvests carried out at 1.5 h intervals. The cell populations consisted of 8.3% interphases, 9.6% prophases, 31.2% metaphases, 5.2% anaphases and 45.7% telophases. The fractions of metaphase and telophase were higher than fractions from exponentially multiplying cultures. Cells completed the subsequent cell cycle in 23 h. The cell cycle stages had the same durations as normal cultures. The storage of harvested cells for 12 to 18 h at 0°C caused a short delay in completion of the first mitosis, but exerted no significant prolongation of the subsequent cell cycle.