Background: Cryopreservation of spermatozoa is an extremely important process in the field of male infertility. High quality preserved spermatozoa has been reported to retain better motility and DNA quality.

Objective: We showed the effect of semen preparation on the quality of cryopreservation of human spermatozoa.

Material and Method: We compared cryopreserved spermatozoa separated by Sil-Select density gradient centrifugation before or after cryopreservation in terms of spermatozoa motility, morphology, and DNA integrity. Spermatozoa’s motility was determined by CASA; the morphology was determined by the eosin-methylene blue staining; and the DNA integrity was determined by TUNEL assay.

Results: We found that semen preparation before or after cryopreservation produced spermatozoa with comparable motility and morphology. However, semen preparation before cryopreservation showed a significantly higher total motile spermatozoa count (8.48 [2.47 to 37.87] vs. 5.35 [0.29 to 17.30], p-value <0.05) and significantly better DNA integrity as indicated by less DNA fragmentation (21.34±3.01 vs. 24.29±3.01, p<0.001).

Conclusion: We concluded that spermatozoa prepared by Sil-Select density gradient centrifugation before cryopreservation can improve quality of the preserved spermatozoa in terms of the total motile spermatozoa count and DNA integrity.

Keywords: Cryopreserved human spermatozoa, Sil-Select density gradient centrifugation, DNA integrity