Authors
Jingmei Hu, M.D., Shidou Zhao, Ph.D., Chengyan Xu, Ph.D., Lin Zhang, M.D., Shaoming Lu, Ph.D., Linlin Cui, Ph.D., Jinlong Ma, Ph.D., Zi-Jiang Chen, Ph.D.
Volume 104, Issue 5, Pages 1253-1257
Abstract
Objective:
To compare the differences in the characteristics of post-thaw human sperm after storage in either liquid nitrogen (LN2; −196°C) or LN2 vapor (−167°C).
Design:
Experimental study.
Setting:
University hospital.
Patient(s):
Thirty healthy volunteers who agreed to donate their normal semen samples for infertility or research were included in the study.
Intervention(s):
Semen samples (n = 30) were divided into eight aliquots and frozen. Four aliquots of each human semen sample were stored in LN2 (−196°C), and the other four aliquots were stored in LN2 vapor (−167°C). After 1, 3, 6, or 12 months, samples were thawed and analyzed.
Main Outcome Measure(s):
The motility was evaluated by the manual counting method. The viability was estimated by eosin staining. The morphology was analyzed by Diff-Quik staining. The sperm DNA integrity was determined with acridine orange fluorescent staining, and acrosin activity was assayed by the modified Kennedy method.
Result(s):
The characteristics of post-thaw human sperm, including motility, viability, morphology, DNA integrity, and acrosin activity, showed no significant difference between LN2 and LN2 vapor storage for the different time periods.
Conclusion(s):
LN2 vapor was comparable to LN2 in post-thaw sperm characteristics, suggesting that LN2 vapor may be substituted for LN2 for the long-term storage of human sperm.
Read the full text at: http://www.fertstert.org/article/S0015-0282(15)01651-9/fulltext