title: Concentrating human sperm before cryopreservation.
abstract: To improve the quality of cryo-preserved sperm, ejaculated semen was concentrated prior to freezing by means of continuous-step density gradient centrifugation. Freezing was simplified by employing liquid nitrogen vapor with KS-II cryo-medium. The original semen (n = 32, 41 +/- 13 x 10(6)/ml, 17 +/- 11% motility) was improved by the processing to be 68 +/- 29 x 10(6)/ml, 55 +/- 19% motility. Even after the specimens were thawed, sperm concentrations were similar to those of the original semen and 39 +/- 18% motility remained with a mean survival rate of 74 +/- 7.7%. The improved sperm motility and higher survival rate resulted in better post-thaw sperm quality than those of the original semen.
authors.affiliation: Department of Obstetrics and Gynecology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: S
authors.initials: S
authors.lastname: Kaneko
authors.forename: I
authors.initials: I
authors.lastname: Hara
authors.forename: Y J
authors.initials: YJ
authors.lastname: Park
authors.forename: H
authors.initials: H
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Ohno
authors.forename: S
authors.initials: S
authors.lastname: Nozawa
mesh_terms: D002470:Cell Survival; D002499:Centrifugation, Density Gradient; D015925:Cryopreservation; D006801:Humans; D008297:Male; D013081:Sperm Motility; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology*