title: The effects of different sperm preparation methods and incubation time on the sperm DNA fragmentation.
abstract: OBJECTIVE
  To study the effect of different sperm preparation methods and incubation times post preparation on sperm DNA fragmentation.
  
  
  METHODS
  Sperm DNA fragmentation was assessed by sperm chromatin dispersion (SCD) method on motile sperm prepared by gradient centrifugation or swim-up and incubated in IVF medium for up to 24 hours. Data were analyzed to discover the effect of preparation methods and incubation times on sperm DNA Fragmentation Index (DFI).
  
  
  RESULTS
  There were no differences in DFI in sperm samples prepared by gradient centrifugation method or swim-up (3.87 ± 2.14 vs. 3.45 ± 1.83, p = 0.544). However, an increase was observed in DFI in samples prepared by swim-up after 6-8 hours compared with by gradient centrifugation (34° vs. 13°, p = 0.04). In the swim-up group, the DFI level at 4 hours was already significantly higher than it was initially. However, following gradient centrifugation, the DFI at 8 hours was significantly higher than the initial DFI level.
  
  
  CONCLUSIONS
  Sperm samples prepared by gradient centrifugation may be more stable, in terms of DNA fragmentation, than samples prepared by swim-up.
authors.affiliation: Chongqing Reproductive and Genetic Institute, Chongqing Obstetric and Gynecology Hospital and Chongqing Medical University, Chongqing, China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Zhang
authors.forename: Min-Yan
authors.initials: MY
authors.lastname: Chen
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.forename: Wei
authors.initials: W
authors.lastname: Han
authors.forename: Dong-Yun
authors.initials: DY
authors.lastname: Liu
authors.forename: Guo-Ning
authors.initials: GN
authors.lastname: Huang
mesh_terms: D000328:Adult; D002469:Cell Separation / Q000379:methods*; D002499:Centrifugation, Density Gradient; D002843:Chromatin / Q000737:chemistry / Q000302:isolation & purification; D003080:Cold Temperature; D053938:DNA Fragmentation; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D027724:Reproductive Techniques, Assisted; D055101:Semen Analysis; D012662:Semen Preservation / Q000379:methods*; D013075:Sperm Capacitation; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism*; D013997:Time Factors; D014019:Tissue Donors
chemical_list: D002843:Chromatin