Magnetic bead-based separation of functionally competent human sperms with hyaluronic acid and its superiority over conventional swim-up and density gradient methods

The selection of competent human sperm influences the successful outcome of Assisted Reproductive Technology. Conventionally used techniques like density gradient and swim-up, use motility-based separation, which may not correlate with the maturity and quality of the sperm. Existing techniques that select mature sperm based on hyaluronic acid binding ability, select very small numbers of sperm, rendering them unsuitable for intra-uterine insemination. We report the development of a new method, USelect that selects and isolates millions of mature sperms based on their ability to bind to hyaluronic acid. Validation of Uselect was done on semen samples (n=40) compared with the conventional methods, like density gradient, and swim up. Subsequently, Uselect selected sperms were used for intra-uterine insemination in a clinical trial (n=50 female patients). Sperm isolated using USelect showed similar mean sperm count and rapid progressive motility compared to SU, but lower than the density gradient method. However, the DNA fragmentation index and hyaluronic acid binding capacity were statistically significant in the USelect sperms that promoted the fertilization rate and showed a higher percentage of biochemical pregnancy (32%, n=16) than density gradient (18%, n=9).