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 its 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: Normozoospermic men could be divided into four subgroups according to the fluorescence pattern of their sperm DNA.

Relationship between sperm quality and chromatin condensation measured by sperm DNA fluorescence using flow cytometry.

DNA flow cytometry of sperm from 100 randomly chosen men undergoing fertility investigation revealed a general association between reduced sperm quality, as judged by conventional parameters, and the appearance of sperm with lower degrees of chromatin condensation in the ejaculate as measured by DNA fluorescence intensity. Chromatin hypocondensation, as measured by increased fluorescence, was manifested to different degrees in different samples. In many cases of more extreme sperm pathology, such as oligoasthenoteratozoospermia (OAT), the whole population of spermatozoa appeared to be affected.

Application of flow cytometry to studies on the human acrosome.

This study describes the use of flow cytometry combined with specific labelling of the human sperm acrosome using a FITC-labelled plant lectin (Arachis hypogea agglutinin). Localization of the label to the acrosome was encouraged by freezing the sperm for at least 24 hours at -70 degrees C prior to labelling. Studies of sperm from 53 normospermic men revealed that acrosome labelling followed a single normal distribution without the presence of subpopulations.