title: Rapid freezing versus slow programmable freezing of human spermatozoa.
abstract: OBJECTIVE
  To compare the efficacy of rapid freezing (RF) and slow programmable freezing (SPF) of human spermatozoa.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  University-based assisted conception laboratory.
  
  
  METHODS
  Semen from 30 normospermic men.
  
  
  METHODS
  Semen was processed through density gradients and divided into three groups: nonfrozen control, RF, and SPF.
  
  
  METHODS
  Sperm motility, kinematics, and morphology were assessed by a computer-assisted semen analyzer; viability by eosin-Y staining and the hypo-osmotic swelling test; DNA integrity by comet assay; and sperm binding by hemi-zona assay.
  
  
  RESULTS
  Post-thaw sperm motility (53.9%, 37.0%, and 75.5% for RF, SPF, and controls, respectively) and sperm vitality (hypo-osmotic swelling test 60.1%, 44.1%, and 77.9%; eosin-Y staining 64.8%, 50.4%, and 81.8% for RF, SPF, and controls, respectively) were higher in the RF than in the SPF group, but lower than in the nonfrozen control group. There was no significant difference in post-thawed normal sperm morphology (14.9%, 14.4%, and 16%) and sperm DNA integrity by comet assay (93.6%, 94.5%, and 94.2%) in the RF, SPF, and controls, respectively. The hemi-zona index was no different between the two cryopreserved groups.
  
  
  CONCLUSIONS
  The RF gave superior post-thaw motility and cryosurvival than SPF.
authors.affiliation: Division of Reproductive Medicine, Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand. tvutyava@mail.med.cmu.ac.th
authors.forename: Teraporn
authors.initials: T
authors.lastname: Vutyavanich
authors.forename: Waraporn
authors.initials: W
authors.lastname: Piromlertamorn
authors.forename: Siriporn
authors.initials: S
authors.lastname: Nunta
mesh_terms: D000328:Adult; D002470:Cell Survival; D015925:Cryopreservation / Q000295:instrumentation / Q000379:methods; D004526:Efficiency; D005615:Freezing; D006801:Humans; D007248:Infertility, Male / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009584:Nitrogen / Q000494:pharmacology; D055101:Semen Analysis; D012662:Semen Preservation / Q000295:instrumentation* / Q000379:methods*; D012984:Software; D013094:Spermatozoa / Q000473:pathology / Q000502:physiology; D013696:Temperature; D013997:Time Factors; D055815:Young Adult
chemical_list: D009584:Nitrogen