Cryoprotectant-free freezing of the goat epididymal sperm.

BACKGROUND

Cryoprotectant free approach successfully removed the impact of physical and chemical damages in preserving human sperm in a vitrification protocol. There is no any report on this technology in farm animal sperm freezing.

OBJECTIVE

The aim of the present study was to find the efficacy of cholesterol-loaded cyclodextrin (CLC; 1 mg per 60 million) and sucrose (0.1 and 0.2 M) on freezing of the goat epididymal sperm.

METHODS

Caudal epididymides (n=5 pairs) were dissected, incised and incubated in the Tris-BSA solution for 15 min, followed by swim-up at room temperature. Sperm was loaded in 0.25 mL French straws and cooled on nitrogen vapor for 3 min then immersed in liquid nitrogen and remained for 48 h. Then the straws thawed by immersing in 37 degree C waterbath for 30 sec and analyzed.

RESULT: The results showed the impact of freezing on the goat epididymal sperm motility, viability and DNA fragmentation that were improved by incorporation of CLC and sucrose (0.2 M).

CONCLUSIONS

In conclusion, the goat epididymal sperm was frozen in a cryoprotectant-free freezing model. CLC and 0.4 M sucrose protected the goat epididymal sperm against freezing-induced damages.