Analysis of in vitro migration patterns of human spermatozoa by a petri dish-based horizontal column

Spermatozoa are required to travel a considerable distance in vivo to meet the oocyte at the fertilization site. However, none of the existing in vitro tests critically evaluates migration of sperm to assess their potential of reaching the oocyte. On the other hand, an in vivo model is not suitable for this type of study because of ethical and technical constraints. In the present study we utilized a horizontal column technique to analyze sperm migration. Migratory characteristics of fresh, unwashed semen sperm and sperm undergoing various treatments were examined in vitro using a Petri dish-based horizontal fluid column. The procedure involved loading a sperm sample into the column and determining sperm concentration, motility, and viability at different column segments for different migration durations (6, 12, 24, 48, and 72 h). All sperm samples produced an exponential migration pattern in all durations of migration. Propagation along the column edge, tendency to exit from the column, and hiding in the blind pouches were some of the important characteristic features exhibited by the migratory sperm. Variations in migration patterns were documented among semen donors, between fresh and frozen semen, and between washed and unwashed sperm. Prolonged postejaculation time diminished migratory potential. The recovery of sperm in the column end was independent of seminal variables with the exception of oligozoospermia. These observations suggest that the Petri dish-based horizontal column is effective for analyzing sperm migration characteristics for prolonged periods. The potential of this migration assay in predicting the in vivo potential of spermatozoa to reach the fertilization site will be worth exploring.