A Method of Short-Term Cryostorage and Selection of Viable Sperm for Use in the Various Assisted Reproductive Techniques

ZAVOS, P.M., CORREA, J.R., SOFIKITIS, N., KOFINAS, G.D. and ZARMAKOUPIS, P.N. A Method of Short-Term Cryostorage and Selection of Viable Sperm for Use in the Various Assisted Reproductive Techniques. Tohoku J. Exp. Med., 1995, 176 (2), 75-81 - The objective of this study was to determine if spermatozoa, following short-term cyostorage at 5°C in Test-Yolk buffer (TYB; ZBL, Inc., Lexington, KY, USA), could be recovered and improved via the SpermPrepTM filtration method and to assess the possibly enhanced fertilizing capacity of the selected spermatozoa. Semen specimens from 20 men were collected, evaluated, diluted 1:1 (v/v) with TYB, divided into aliquots and cooled to 5°C for 24 and 48hr. Semen samples were assessed for volume, sperm count, percentage and grade of motility, percentage of morphologically normal spermatozoa and outcome of the sperm penetration assay (SPA). After storage, aliquots were rewarmed at 37°C, centrifuged, and the pellet was resuspended in 1.0ml of SpermPrepTM media (ZBL, Inc.). Following 15min of incubation, the rewarmed spermatozoa were filtered via the SpermPrepTM I filtration column (ZBL, Inc.) and assessed accordingly. The results obtained in this study indicate that the short-term cryostorage procedure yielded spermatozoa of adequate qualitative characteristics when compared to the fresh spermatozoa. Furthermore, filtration of rewarmed specimens yielded spermatozoa of significantly higher qualitative characteristics and superior fertilizing capacity following a short-term cyostorage period in TYB when compared to fresh and rewarmed spermatozoa (p