Comparison of the effects of two methods of cryopreservation on testicular sperm DNA.
OBJECTIVE
To assess the effects of two methods of freezing on testicular sperm DNA from subjects with obstructive azoospermia and to compare these with samples of fresh and freeze-thawed testicular sperm from fertile men.


METHODS
The Comet assay was used to determine the percentage of undamaged DNA in fresh testicular sperm, testicular sperm freeze-thawed in suspension and in a biopsy sample (men with obstructive azoospermia), and in fresh and freeze-thawed testicular sperm (fertile men).


METHODS
The Regional Fertility Center, Royal Maternity Hospital, Belfast, Northern Ireland, United Kingdom.


METHODS
Twelve males with obstructive azoospermia (normal testicular volume and hormone profiles) and nine fertile control subjects.


METHODS
Trucut needle testicular biopsy under local anesthetic.


METHODS
Measurement of the percentage of undamaged DNA in fresh and freeze-thawed testicular sperm using the Comet assay.


RESULTS
No significant difference was found between the percentage of undamaged DNA of fresh testicular sperm and of both types of freeze-thawed testicular sperm. There was also no significant difference between the percentage of undamaged DNA in fresh or freeze-thawed testicular sperm from controls. Control ejaculated sperm DNA was significantly more damaged than testicular sperm DNA from control men.


CONCLUSIONS
Cryopreservation of testicular sperm does not increase baseline levels of DNA damage.
Steele
E K
EK
Department of Obstetrics and Gynecology, The Queen's University of Belfast, Institute of Clinical Science, Northern, Belfast, Ireland.
McClure
N
N
Lewis
S E
SE
D001706:Biopsy; D015925:Cryopreservation / Q000379:methods; D004247:DNA / Q000737:chemistry*; D004249:DNA Damage; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007621:Karyotyping; D008297:Male; D009845:Oligospermia / Q000473:pathology; D012662:Semen Preservation / Q000379:methods*; D013737:Testis / Q000473:pathology
D005640:Follicle Stimulating Hormone; D004247:DNA