title: A new method of the electrolyte-free long-term preservation of human sperm at 4 degrees C.
abstract: OBJECTIVE
  To develop a new method for the long-term preservation of human sperm.
  
  
  METHODS
  Andrology laboratory of our hospital.
  
  
  METHODS
  Thirty-one normal and 19 asthenozoospermic semen samples obtained from patients attending our infertility clinic. The average sperm motility was 70.2% and 36.0% in the normal and asthenozoospermic groups, respectively.
  
  
  METHODS
  Ejaculated sperm were centrifuged and washed using the electrolyte-free Percoll gradient and then were preserved at 4 degrees C.
  
  
  METHODS
  The motility of the preserved sperm was analyzed using computer-assisted semen analyzer after the addition of Ham's modified F-10 (GIBCO, Grand Island, NY).
  
  
  RESULTS
  In the normal group, motility rate after the addition of Ham's F-10 for 1, 2, and 4 weeks of preservation was 65.4%, 40.4%, and 5.5%, respectively. In the asthenozoospermic group, motility rate after 1 and 2 weeks of preservation was 31.3% and 18.1%, respectively. Preservation solutions containing sodium or potassium decreased motility after preservation. Restoration of preserved sperm was not achieved by incubation alone; however, reinitiation was induced by incubation together with Ham's F-10.
  
  
  CONCLUSIONS
  Human sperm in the electrolyte-free solution survived for a long period of time at 4 degrees C and reinitiation of sperm motility after preservation required the addition of Ham's F-10.
authors.affiliation: Department of Urology, Yokohama City University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Saito
authors.forename: Y
authors.initials: Y
authors.lastname: Kinoshita
authors.forename: H
authors.initials: H
authors.lastname: Kanno
authors.forename: A
authors.initials: A
authors.lastname: Iwasaki
authors.forename: M
authors.initials: M
authors.lastname: Hosaka
mesh_terms: D003080:Cold Temperature; D006801:Humans; D007248:Infertility, Male / Q000503:physiopathology; D008297:Male; D011188:Potassium; D012662:Semen Preservation / Q000379:methods*; D012964:Sodium; D012996:Solutions; D013081:Sperm Motility; D013997:Time Factors
chemical_list: D012996:Solutions; D012964:Sodium; D011188:Potassium