![Sample our Bioscience journals, sign in here to start your access, Latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5925/TOC-Subject-Sample-2021-Bioscience.jpg"})
Abstract
The article describes the technical strategies for clinical cryogenic preservation of low-quality human semen. To compensate for sperm dilution resulting from the use of a cryogenic medium, ejaculated semen was concentrated before freezing by means of continuous-step density gradient centrifugation. Freezing was simplified by employing the carbon dioxide pellet method with KS-II cryogenic medium, which contains Pluronic F-68, a nonionic detergent, to solubilize egg yolk (a major cryogenic protect-ant). Semen of less than 50% motility (n = 23) was processed and then cryogenically preserved. Sperm concentration was increased by a factor of 1.8 ± 0.96 (n - 23). Sperm motility was improved from 35.9% ± 13.9% to 69.4% ±10.8%. Even after thawing 59.4% ± 17.5% motility remained, with a mean survival rate of 85% ±14%. The concentration of sperm and improved sperm motility by the use of the continuous-step density gradient and the high survival rate ensured by the carbon dioxide pellet method with KS-II cryogenic medium compensated for the lowering of sperm quality during cryogenic preservation.