[Evaluation of microporous membrane optimizer in reducing sperm DNA fragmentation index]

Objective The aim of this study is to evaluate the effect of microporous membrane optimizer （MMO）on reducing sperm DNA fragmentation index （DFI）. Methods The discarded semen of 60 infertile males were randomly selected. Swim-up method, density-gradient centrifugation techniques and MMO were used for sperm preparation. Then sperm concentration, motility, sperm DNA fragmentation, intracellular H2O2 and mitochondrial O2－ level were measured respectively and compared with fresh semen. Results Compared with fresh semen, sperm motility and progressive motility prepared by swim-up, density gradient centrifugation and MMO were significantly increased, and DFI decreased significantly（P<0.01）. There was no significant difference in the H2O2 levels within the sperm cells prepared by the three methods (P>0.05). However, the O2－ level in the sperm mitochondria by density-gradient centrifugation significantly increased (P<0.05), while the O2－ level in the sperm mitochondria by MMO significantly decreased (P<0.05).Conclusions For random samples, MMO is an effective method for selecting sperm with higher motility, lower sperm DNA fragmentation, and lower mitochondrial O2－ levels. There are individual differences in sperm optimization methods among different semen samples.