Figure 1:

Ensemble measurements can mask the variation in the kinetics of repair between cells. The kinetics of DNA DSB repair are popularly measured by averaging the number of foci in groups of fixed cells at specific times after damage. Such measurements do not capture the natural variation in the population and can mask the true kinetics of repair in single cells. (A) Left—a homogeneous population that repairs rather uniformly and right—a heterogeneous population that exhibits bimodality in the rates of repair; both yield the same average measurements at different times after damage. (B) The decay in the number of foci for three different cells is shown. Each of these cells has unique kinetics of repair, however, would yield the same number of foci if fixed at the indicated times.