title: Hamster egg penetration: comparison of preincubation periods.
abstract: Seven-hour and 20-hour incubation periods were tested with donor specimens to be used in the hamster egg sperm penetration assay (SPA). Aliquots of the washed sperm were incubated in air and in 5% CO2 and 95% air at 37 degrees C for comparison of sperm survival rates. The mean penetration for the donors ranged from 0% to 64%, with group means of 21% and 36% for the 7- and 20-hour incubations, respectively. All donors had penetration rates in the fertile range after 20 hours of incubation, but 33% (3 of 9) had penetration rates less than 10% after 7 hours of incubation. Incubation of sperm in air reduced the motility by 9% after 20 hours. The results suggest that the 20-hour incubation in 5% CO2 is better because it reduces the possibility of false-negative results in the SPA. We conclude that penetration in the questionable range of 10% may require further SPA testing with different incubation periods and technique modifications, such as a sperm rise step to increase sperm motility and reduce the number of leukocytes.
mesh_terms: D000818:Animals; D006224:Cricetinae; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D006801:Humans; D007248:Infertility, Male / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D010063:Ovum / Q000502:physiology*; D013048:Specimen Handling / Q000379:methods; D013075:Sperm Capacitation; D013081:Sperm Motility; D013084:Sperm-Ovum Interactions; D013997:Time Factors