Cell kinetics of the K-562 cell line in microculture

The cell kinetic parameters of K-562 leukemia cells were studied using microwell cultures in which growth was initiated from a single cell. Total population growth was studied by direct enumeration, 3H-thymidine labelling, and flow cytometry. Clonogenic cell growth was studied by replating and 3H-thymidine suicide. In 7-day clones of K-562 cells, durations of the total cell cycle, G1, S, G2, and M phases were 20.8 h, 3.5 h, 12.9 h, 3.3 h, and 1.1 h, respectively; the growth fraction was 0.92 and the cell loss factor was 0.084. Study of colony-forming cells by replating indicated that clonogenic cells comprised 40% of total cells. 3H-Thymidine suicide showed that cell-cycle duration for these cells was 22.5 h and that S-phase duration was 11.7 h.