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The effects of different sperm preparation methods and incubation time on the sperm DNA fragmentation
Xiao-Dong Zhang1, Min-Yan Chen, Yang Gao
1Chongqing Reproductive and Genetic Institute, Chongqing Obstetric and Gynecology Hospital and Chongqing Medical University, Chongqing, China.
Purpose:
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.
Conclusion:
Sperm samples prepared by gradient centrifugation may be more stable, in terms of DNA fragmentation, than samples prepared by swim-up.
