Does ICSI require acrosomal disruption?
The Center for Reproductive Medicine and Infertility, Weill Medical College of Cornell University, 505 East 70th Street, HT-336, New York, NY 10021, USA.BACKGROUND: Aggressive immobilization of sperm prior to ICSI significantly improves fertilization rates, but the mechanism of this effect is not yet clear. This study was performed in order to assess the characteristics of mechanically immobilized human sperm by transmission electron microscope (TEM). METHODS: Sperm obtained from ejaculated semen samples from three different donors were immobilized in a standard manner for ICSI. They were then injected into the perivitelline space of mouse oocytes in order to be able to locate them by TEM. Intact motile sperm injected subzonally served as controls (n=160). Finally, the ‘carrier’ oocytes were fixed and processed for TEM. RESULTS: A total of 300 sperm were mechanically immobilized and inserted into the perivitelline space of mouse oocytes. Ultrathin sections revealed consistent alteratio
