Basic and clinical aspects of Sperm Chromomycin A3 assay.

Semen quality is conventionally determined according to the number, motility, and morphology ofspermatozoa in an ejaculate. In turn, it is generally accepted that an association exists between these semenparameters and fertilizing ability. With the advent of in vitro fertilization (IVF) and related techniquessuch as intracytoplasmic sperm injection (ICSI), it has become increasingly apparent that the number,motility, and morphology of spermatozoa are not always indicative of a male’s fertility status. Methodsexploring sperm DNA stability and integrity have been applied during the last decade to evaluate fertilitydisorders and to increase the predictive value of sperm analysis for procreation in vivo and in vitro. It hasbeen shown that infertile men have an increased sperm histone–protamine ratio than fertile counterparts.This alteration of histone–protamine ratio, also called abnormal packing, increases susceptibility of spermDNA to external stresses due to poorer chromatin compaction. Recent studies have also underlined the linkbetween protamine deficiency and sperm DNA damage that resulted in poor fertilizing capacity.