Diluent for frozen human sperm, dilution method for frozen human sperm, and adjustment method for human semen for in vitro fertilization or semen for artificial insemination
Provided are a diluent for frozen human sperm which can suppress the decrease in sperm motility after melting the frozen human sperm, a dilution method for frozen human sperm, and an adjustment method for human semen for in vitro fertilization or semen for artificial insemination. The diluent for frozen human sperm contains a chelating agent forming a complex with a calcium ion, and has the pH of 6.75 or more but less than 7.4. The chelating agent is preferably EGTA, and preferably has the pH of 6.9 to 7.1. The dilution method for frozen human sperm includes melting frozen human sperms and mixing the human sperms with the diluent for frozen human sperm. Further, after the initiation of melting, the sperms are isolated from the diluent for frozen human sperm within a predetermined period of time.