Cell kinetics of normal and perturbed populations measured by incorporation of bromodeoxyuridine and flow cytometry

Bromodeoxyuridine (BrdU) incorporation and flow cytometry have been used to measure the kinetics of V79 cells growing at different temperatures in vitro and cells of the murine Sa F tumour growing in vivo. By simultaneously measuring total DNA content and BrdU incorporation in individual cells at different times after pulse labelling with BrdU, it is a simple procedure to quantify the movement of cells through the cell cycle. The method has the advantage of speed (2 X 10(4) or more cells are analysed within a day or so of the experiment) and the ability to analyse the results in different ways. A G2 block in tumour cell progression in vivo is readily detected after a dose as low as 2 Gy. The neutron relative biological effectiveness for this G2 block is probably larger than that for tumour growth delay.