DNA FLOW-CYTOMETRY OF SPERM FROM NORMOZOOSPERMIC MEN IN BARREN COUPLES AND MEN OF PROVEN FERTILITY

Objective-To determine the extent to which sperm chromatin varies in i ts degree of condensation in 53 apparently normozoospermic men and in 14 men of proven fertility. Methods-DNA flow cytometry after staining of spermatozoa with ethidium bromide and mithramycin. Results-Normozoo spermic men could be divided into four subgroups according to the fluo rescence pattern of their sperm DNA. More than half of the normozoospe rmic group and all of those of proven fertility shared a similar profi le with a narrow symmetrical peak of haploid fluorescence without sign ificant sub-populations. Deviations from this pattern were generally n ot associated with any major differences in sperm quality. Conclusions -a) Current criteria for normozoospermia should be expanded to include additional tests of biochemical integrity. (b) Fertilizing ability ap pears to be associated with a relatively homogeneous profile of sperm DNA condensation.