title: Reduced senescence and retained nuclear DNA integrity in human spermatozoa prepared by density gradient centrifugation.
abstract: OBJECTIVE
  To investigate whether removal of extraneous cells and immotile spermatozoa from a sperm preparation by density gradient centrifugation could help to maintain normal spermatozoa in a viable state and retain their deoxyribonucleic acid integrity.
  
  
  METHODS
  Sperm motility was assessed on a daily basis in aliquots of neat semen, extended semen, and spermatozoa prepared on a PureSperm density gradient. At the same time, aliquots of each sperm sample were preserved for TUNEL assay and nick translation.
  
  
  RESULTS
  Spermatozoa prepared using density gradient centrifugation survived three times as long as spermatozoa in neat semen or in extended semen. Both deoxyribonucleic acid integrity and sperm motility were retained in the gradient preparations.
  
  
  CONCLUSIONS
  Preparing spermatozoa by density gradient centrifugation is advantageous in prolonging sperm survival and maintaining deoxyribonucleic acid integrity, presumably by removing sources of reactive oxygen species. Stored spermatozoa could be used for a second attempt at fertilization if oocyte immaturity was suspected.
authors.affiliation: Nidacon International, Gothenburg, Sweden. jane.morrell@telia.com
authors.forename: J M
authors.initials: JM
authors.lastname: Morrell
authors.forename: O
authors.initials: O
authors.lastname: Moffatt
authors.forename: D
authors.initials: D
authors.lastname: Sakkas
authors.forename: G C
authors.initials: GC
authors.lastname: Manicardi
authors.forename: D
authors.initials: D
authors.lastname: Bizzaro
authors.forename: M
authors.initials: M
authors.lastname: Tomlinson
authors.forename: H
authors.initials: H
authors.lastname: Nilsson
authors.forename: P V
authors.initials: PV
authors.lastname: Holmes
mesh_terms: D000328:Adult; D002467:Cell Nucleus / Q000648:ultrastructure*; D002469:Cell Separation / Q000379:methods; D002470:Cell Survival; D016922:Cellular Senescence / Q000502:physiology*; D002499:Centrifugation, Density Gradient / Q000379:methods; D004247:DNA / Q000032:analysis*; D006801:Humans; D008297:Male; D012662:Semen Preservation; D013081:Sperm Motility; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology*
chemical_list: D004247:DNA