IMPROVED MOTILE SPERM RECOVERY BY A HYPEROSMOTIC PERCOLL GRADIENT

Purpose: Our purpose was to investigate whether a new, relatively hype rosmotic Percoll gradient, Enhance-S, can improve total motile sperm r ecovery rates compared with the commonly used Percoll gradient Percept ion. Methods: Semen specimens from each of 17 donors were divided into two equal aliquots. One part was washed using Percoll Perception, whi le the other was prepared using Percoll Enhance-S. Results: Compared t o the unwashed specimen, sperm motion characteristics (motility and ve locity) improved significantly after Percoll separation using either t he Perception or the Enhance-S gradient. There was no difference in mo tility or velocity in spermatozoa recovered after wash with either of the two preparations. However the total motile sperm recovery was sign ificantly higher using the Percoll Enhance-S gradient than with the Pe rcoll Perception gradient (P < 0.0024). Conclusion: The new Percoll En hance-S gradient provides significantly more total motile sperm than t he Percoll Perception gradient.