The use of hyaluronic acid for sperm selection--evaluation of sperm head ultrastructure

The percentage of normal spermatozoal plasma membranes and acrosomes was evaluated by electron microscopy before and after a two-step semen washing and swim-up into culture medium containing either bovine serum albumin or hyaluronic acid. Both techniques of sperm selection increased the concentration of motile spermatozoa when compared with the fresh ejaculate (P less than .001). The percentage of sperm with ultrastructurally intact plasma membranes and acrosomes was increased after both separation procedures in comparison with the original ejaculate (P less than .01). In addition, both techniques of sperm selection significantly reduced the content of sample debris, granulocytes, and nonviable spermatozoa (P less than .01).