Automatic scoring of sister chromatid exchanges by image analysis in a dose response experiment

Abstract

A system which automatically selects second division metaphases and then, automatically scores the number of seEs of each cell is described. In on initial set of experiments, the performance of the components of the system was measured using a doto set in which metophases had been visually classified as either 2nd division or other; and in 2nd division metaphoses, every SeE had been marked on a hard copy. seE scoring had a true positive rate of about 75% and a false positive rate of about 1.5 false SeEs per metaphase analyzed. Second division detection hod a true positive rate of 80% and a false positive rate of about 10% of the non-2nd division cells. Next, the overall system was compared to human visual scoring in a dose-response experiment by analyzing the effect of mitomycin C on human chromosomes scored visually by two observers and by the fully automatic scoring. Human visual scoring and machine analysis showed similar dose responses, but the variability between them was considerable.