Advantage of combining magnetic cell separation with sperm preparation techniques.

The selection of vital, non-apoptotic spermatozoa is a prerequisite for achieving optimal conception rates in assisted reproductive techniques. Magnetic cell sorting using annexin-V microbeads can effectively separate apoptotic and non-apoptotic spermatozoa. The objective of the present study was to optimize the integration of magnetic cell sorting in standard sperm preparations and to correlate the effect of different sperm preparation procedures on apoptotic markers. Semen specimens collected from 15 healthy donors were prepared by either density gradient centrifugation or by one-step sperm wash technique separately and in combination with magnetic cell sorting. The preparation methods were evaluated by assessment of semen parameters (motility, viability and morphology) as well as markers of apoptosis (levels of active caspase-3, integrity of membrane mitochondrial potential and externalization of phosphatidylserine). The apoptotic markers were measured using fluorochrome dyes coupled with flow cytometry. The results showed that the combination of density gradient centrifugation and annexin-V magnetic cell sorting was superior to all other sperm preparation methods in terms of providing motile, viable and non-apoptotic spermatozoa. This study clearly shows the advantage of integrating magnetic cell sorting as a part of sperm preparation, which in turn may positively affect the success rates of assisted reproductive techniques.