Ogle RA, Netherton J, Schneider E, et al. - This study was undertaken to investigate the nuclear heterogeneity of high-density purified human spermatozoa typically used for IVF purposes. Researchers correlated the intensity of Chromomycin A3 (CMA3) binding within high-dense sperm populations obtained from men. They validated binding heterogeneity through fluorescence microscopy and FACS analysis independently. They obtained semen after 2 days abstinence and purified over Percoll gradients. The data showed that CMA3 is one of the better reported prognostic assays in predicting pregnancy outcomes, particularly in cases where the male is at fault. Nevertheless, it is confirmed that even in fractionated populations of human spermatozoa, there are sperm cells that are morphologically normal yet possess high levels of CMA3 staining and chromatin granulation.