Cryopreservation of a Small Number of Human Sperm within Empty Zona Pellucidae

Objective To investigate the empty zona pellucida for use in the cryopreservation ofhuman sperm.Materials & Methods Human and hamster zona pellucidae were evacuated andinjected with testicular, epididymal and ejaculated sperm. The zona pellucidae withsperm were cryopreserved.Results After thawing, zona pellucidae were easily found, and sperm inside zonapellucidae were also easily observed. There were no differences in post-thaw motilityand vitality between ejaculated and epididymal sperm groups (P ＞ O. 05), but thesetwo parameters were lowered in testicular sperm group compared to both ejaculatedand epididymal sperm (P ＜ O. 01). No significant difference was observed inpost-thaw motilities among 6%, 7. 5%, 9% glycerol concentrations (P＞ O. 05). Inaddition, obvious differences in post-thaw motilities were not found between humanand hamster empty zona pellucidae (P＞ O. 05).Conclusion An evacuated zona pellucida is an ideal vehicle for the cryopreservationof a small number of human sperm.