title: Potential adverse effect of semen processing on human sperm deoxyribonucleic acid integrity.
abstract: OBJECTIVE
  To examine the effect of standard Percoll density-gradient centrifugation on human sperm DNA denaturation.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  University-based infertility clinic.
  
  
  METHODS
  Twenty-five nonazoospermic men.
  
  
  METHODS
  Semen samples (n = 25) were obtained from consecutively seen nonazoospermic men presenting for infertility evaluation. Samples were processed by two-layer and four-layer Percoll density gradients. Sperm motility and sperm chromatin structure (evaluated by flow cytometry analysis of acridine orange-treated spermatozoa) were monitored before and after semen processing. Sperm chromatin integrity was expressed as the percentage of spermatozoa that demonstrated denatured DNA.
  
  
  METHODS
  Sperm motility and DNA integrity.
  
  
  RESULTS
  Mean sperm motility improved significantly after processing with two-layer and four-layer Percoll gradients compared with whole semen (54% and 57% motility versus 44% motility, respectively). In contrast, the percentage of sperm with denatured DNA increased after processing with two-layer and four-layer Percoll gradients compared with whole semen (34% and 32% versus 18%, respectively).
  
  
  CONCLUSIONS
  Our data demonstrate that the improvement seen in sperm motility after Percoll processing is not associated with a similar improvement in sperm DNA integrity. These data suggest that we reexamine current sperm processing techniques to minimize sperm DNA damage and the potential transmission of genetic mutations in assisted reproductive cycles.
authors.affiliation: Department of Surgery, Mount Sinai Hospital, University of Toronto, Ontario, Canada. azini@mtsinai.on.ca
authors.forename: A
authors.initials: A
authors.lastname: Zini
authors.forename: V
authors.initials: V
authors.lastname: Mak
authors.forename: D
authors.initials: D
authors.lastname: Phang
authors.forename: K
authors.initials: K
authors.lastname: Jarvi
mesh_terms: D000165:Acridine Orange / Q000494:pharmacology; D002499:Centrifugation, Density Gradient; D002843:Chromatin / Q000648:ultrastructure; D004247:DNA / Q000737:chemistry*; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D009691:Nucleic Acid Denaturation; D009845:Oligospermia / Q000473:pathology*; D011446:Prospective Studies; D012661:Semen; D013048:Specimen Handling / Q000009:adverse effects*; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D002843:Chromatin; D004247:DNA; D000165:Acridine Orange