Detection and measurement of single-strand breaks in nuclear DNA in fixed lens sections

Ethanol-fixed lens sections were incubated with calf-thymus terminal deoxynucleotidyl transferase and 3H-dATP, and the time-course of 3H-dAMP incorporation was compared among various lens cell types by quantitative autoradiography. The data show that the proportion of cell nuclei containing DNA with single-strand breaks increases during fiber cell differentiation, and that the relative number of breaks per nucleus or unit nuclear area also increase in the same sequence.