Penetrating capacity of human spermatozoa cool preserved in electrolyte-free solution

Objective: To evaluate whether human spermatozoa preserved in electrolyte-f ree (EF) solution at 4 degreesC possess normal penetrating capacity. Study design: The acrosomal status of human spermatozoa cool preserved in E F solution was evaluated before preservation and before and after reinitiat ion by using chlortetracycline staining. The zona-free hamster egg sperm pe netration test was performed using spermatozoa cool preserved in EF solutio n. Results: The percentages of capacitated and acrosome-reacted spermatozoa co ol preserved in EF solution before reinitiation were similar to those of fr esh spermatozoa, but they significantly increased after reinitiation. The p enetration rate and fertility index of spermatozoa cool preserved in EF sol ution were comparable to those of fresh spermatozoa (48.3% vs. 50.8% and 1. 37 +/-0.15 vs. 1.29 +/-0.10, respectively). Conclusion: Human spermatozoa cool preserved in EF solution for one week ca n possess as much penetrating capacity as fresh spermatozoa.