Spermatozoa isolation with Felix™ outperforms conventional density gradient centrifugation preparation in selecting cells with low DNA damage.

Background: The optimization of spermatozoa preparation techniques in order to obtain cell fractions enriched with structurally and functionally "superior" spermatozoa is a key objective of the assisted reproduction industry. Objectives: The purpose of this study was to evaluate a recent development of an electrophoretic spermatozoa separation device (Felix™, Memphasys Ltd, Sydney, Australia) and to compare its performance with conventional spermatozoa preparation by density gradient centrifugation (DGC). Particular attention was paid to the evaluation of sperm DNA/nuclear integrity. Materials & methods: A cohort of 29 human semen samples was studied. Semen samples were analyzed fresh and after DGC or Felix™ preparation. Semen parameters monitored included sample volume, sperm count, total motility, progressive motility, sperm DNA fragmentation using the Sperm Chromatin Structure Assay and sperm DNA oxidation. Results: Spermatozoa preparation with Felix™ resulted in significantly improved spermatozoa fractions with higher progressive motility, lower sperm DNA fragmentation, and lower sperm DNA oxidation compared with raw semen and DGC‐prepared spermatozoa. Discussion & conclusion: The data collected in this study support the preparation of spermatozoa by the Felix™ system as it allows selection of spermatozoa with the highest progressive motility as well as the lowest nuclear/DNA damage. These improved sperm parameters, along with the fact that the Felix™ separation process is very fast and highly standardized, should be of great interest to the assisted reproduction technologies industry. [ABSTRACT FROM AUTHOR]