Concentration of viable spermatozoa for artificial insemination.

Glass wool microfiber code 112 (approximately 30 mg) was gently packed to a depth of 3 mm in a 3-ml disposable syringe barrel. The column was rinsed repeatedly with Tyrode solution to remove loose glass wool fibers. Approximately 0.3 to 0.5 ml of concentrated spermatozoa (after centrifugation of semen at 500 X g for 5 minutes) was layered over the wet column and allowed to filter by gravity. The filtered spermatozoa demonstrated a significantly higher (P less than 0.001) mean percentage of motility, progressive motility, sperm unstained by eosin Y dye, and sperm with functionally intact membranes. Although there was a considerable loss of sperm, the filtered specimen contained all viable spermatozoa present before filtration. Therefore, it appears that this procedure yields a high percentage of viable spermatozoa, potentially capable of fertilization, for use in in vitro fertilization or, possibly, artificial insemination.