title: Multistep and single-step treatment of human spermatozoa with cryoprotectants.
abstract: OBJECTIVE
  To compare the impact of multi- and single-step addition of cryoprotectants on human spermatozoa.
  
  
  METHODS
  Human semen was subjected to cryoprotective agents (CPAs) in both one-step and multistep protocols before removal of the CPAs by multi-step and single-step methods.
  
  
  METHODS
  Infertility clinic.
  
  
  METHODS
  Healthy normozoospermic volunteers.
  
  
  METHODS
  Single- and multistep addition and removal of a range of CPAs.
  
  
  METHODS
  Analysis of tail morphology and total and progressive motility, as well as kinematic parameters, in medium and sperm penetration into artificial mucus.
  
  
  RESULTS
  While no CPA drastically affected sperm vitality, some were more deleterious than others. Propane-1,3-diol was the least damaging to sperm function, whereas glycerol and ethyl(hydroxymethyl)propane were particularly disruptive. For all CPAs, multistep addition and removal of CPAs proved less damaging to sperm function than the single-step protocol.
  
  
  CONCLUSIONS
  Optimal CPAs may be those that minimize osmotic stresses to spermatozoa during prefreeze and post-thaw procedures.
authors.affiliation: Institute of Reproductive Medicine of the University, Domagkstrasse 11, Münster, Germany.
authors.forename: Dyah
authors.initials: D
authors.lastname: Widiasih
authors.forename: Ching-Hei
authors.initials: CH
authors.lastname: Yeung
authors.forename: Aris
authors.initials: A
authors.lastname: Junaidi
authors.forename: Trevor G
authors.initials: TG
authors.lastname: Cooper
mesh_terms: D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D006801:Humans; D008297:Male; D012016:Reference Values; D012662:Semen Preservation / Q000379:methods*; D013081:Sperm Motility / Q000187:drug effects; D013084:Sperm-Ovum Interactions / Q000187:drug effects; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology
chemical_list: D003451:Cryoprotective Agents