A Simple Confocal Microscopy-based Method for Assessing Sperm Movement

In the field of reproductive medicine, assessment of sperm motility is a key factor for achieving successful artificial insemination, in vitro fertilization, or intracellular sperm injection. In this study, the motility of boar sperms was estimated using real-time imaging via confocal microscopy. To confirm this confocal imaging method, flagellar beats and whiplash-like movement angles were compared between fresh and low-temperature-preserved (17℃ for 24 h) porcine sperms. Low-temperature preservation reduced the number of flagellar beats from 11.0±2.3 beats/s (fresh sperm) to 5.7±1.8 beats/s and increased the flagellar bending angle from 19.8°±13.8° (fresh) to 30.6°±15.6°. These data suggest that sperm activity can be assessed using confocal microscopy. The observed motility patterns could be used to develop a sperm evaluation index and automated confocal microscopic sperm motility analysis techniques.