Pm. Zavos et al., A METHOD OF SHORT-TERM CRYOSTORAGE AND SELECTION OF VIABLE SPERM FOR USE IN THE VARIOUS ASSISTED REPRODUCTIVE TECHNIQUES, Tohoku Journal of Experimental Medicine, 176(2), 1995, pp. 75-81
The objective of this study was to determine if spermatozoa, following
short-term cryostorage at 5 degrees C in Test-Polk buffer (TYB; ZBL,
Inc., Lexington, KY, USA), could be recovered and improved via the Spe
rmPrep(TM) filtration method and to assess the possibly enhanced ferti
lizing capacity of the selected spermatozoa. Semen specimens from 20 m
en mere collected, evaluated, diluted 1:1 (v/v) with TYB, divided into
aliquots and cooled to 5 degrees C for 24 and 48 hr. Semen samples we
re assessed for volume, sperm count, percentage and grade of motility,
percentage of morphologically normal spermatozoa and outcome of the s
perm penetration assay (SPA). After storage, aliquots were rewarmed at
37 degrees C, centrifuged, and the pellet was resuspended in 1.0 ml o
f SpermPrep(TM) media (ZBL, Inc.). Following 15 min of incubation, the
rewarmed spermatozoa, were filtered via the SpermPrep(TM) I filtratio
n 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 y
ielded spermatozoa of significantly higher qualitative characteristics
and superior fertilizing capacity following a short-term cryostorage
period in TYB when compared to fresh and rewarmed spermatozoa (p < 0.0
5). This method of short-term cryostorage in TYB and selection of supe
rior spermatozoa via the SpermPrep(TM) filtration method could further
enhance the fertilizing ability of patients who produce spermatozoa c
haracterized by deficient capacitation acrosome reaction and subsequen
t fertilization.