THE INFLUENCE OF A MINERAL-OIL OVERLAY ON THE ZONA-PELLUCIDA BINDING POTENTIAL OF HUMAN SPERMATOZOA

The objective of the study was to evaluate the effect of mineral oil o n zona pellucida binding potential of human spermatozoa. The study com pared zona binding using micro volume droplets under mineral oil as ap posed to micro droplets in cryopreservation straws. Spermatozoa from e ight proven fertile sperm donors were used. One hundred and fifty five matched hemizonae in 50 mu l, 100 mu l and 200 mu l insemination sper m droplets were co-incubated; (i) under mineral oil and (ii) 0.5 ml pl astic cryopreservation straws. The results were analysed to determine the number of the zona bound spermatozoa during each experiment. Micro volumes with an oil overlay had a decrease in sperm bound per hemizona of 38% (mean +/- SD; 563 +/- 415 vs. 921 +/- 597), 51% (mean +/- SD; 392 +/- 359 vs. 800 +/- 566 sperm) and 18% (mean +/- SD; 502 +/- 369 v s. 618 +/- 445) in 200 mu l, 100 mu l and 50 mu l respectively, compar ed to microvolumes in cryopreservation straws. It was concluded that m ineral oil may have some detrimental factors which interfere with zona binding of spermatozoa.