title: Interrelationships between seminal parameters and sperm nuclear DNA damage before and after density gradient centrifugation: implications for assisted conception.
abstract: BACKGROUND
  With an increase in the use of assisted reproduction technologies the requirements of the diagnostic semen analysis are constantly changing.
  
  
  METHODS
  Spermatozoa from patients undergoing IVF were analysed by examining the conventional semen parameters and DNA/chromatin integrity, using in-situ nick translation (NT) and the Chromomycin A(3) fluorochrome, which indirectly demonstrates a decreased presence of protamine. Samples were examined before and after preparation using discontinuous density gradient centrifugation.
  
  
  RESULTS
  Density gradient centrifugation enriched samples by improving the percentage of morphologically normal forms by 138% and sperm nuclear integrity by 450%. Sperm nuclear integrity as assessed by in-situ nick translation (NT) demonstrated a very clear relationship with sperm concentration, motility and morphology. Morphology correlated with fertilization rates of patients undergoing IVF, while NT values of the spermatozoa post-preparation were significantly lower in pregnant patients.
  
  
  CONCLUSIONS
  We have demonstrated that along with the classical semen parameters, the assessment of nuclear integrity improves the characterization of the semen sample and may be used as a tool for allocating patients to specific assisted reproduction treatments.
authors.affiliation: Assisted Conception Unit, Birmingham Women's Hospital, Birmingham, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Tomlinson
authors.forename: O
authors.initials: O
authors.lastname: Moffatt
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: Afnan
authors.forename: D
authors.initials: D
authors.lastname: Sakkas
mesh_terms: D000328:Adult; D002467:Cell Nucleus / Q000502:physiology*; D002499:Centrifugation, Density Gradient; D004249:DNA Damage; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D012099:Reproductive Techniques; D012661:Semen / Q000502:physiology*; D013076:Sperm Count; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure