Motility
measurements were performed within 15 s following sperm
activation. Sperm cells that vibrated in place were not considered
to be motile. For cryopreservation experiments, sperm samples
showing below 80% motility were discarded. Following addition of the activation solution to the sperm samples, duration of sperm
motility was determined using a sensitive chronometer (sensitivity:
1/100 s) by recording the time until all spermatozoa movements
have stopped. Approximately twenty spermatozoa were
counted for each examination area on a glass slide and totally sixty
spermatozoa were observed by using three different evaluation
areas for the same straw