Sperm cryopreservation methods.

There are multiple clinical situations where cryopreservation of sperm is required including sperm banking prior to chemotherapy or radiation treatment for cancer, donor sperm for couples without a male partner, and various etiologies of male factor infertility. Bunge and Sherman presented the first pregnancy resulting from the thawing of cryopreserved sperm in 1953 (Bunge RJ, Nature 172:767-768, 1953). Since that time, cryopreservation techniques have continued to improve. Here, we describe protocols for the cryopreservation and thawing of semen and testicular tissues using a simple liquid nitrogen vapor technique.