Testicular tissue cryopreservation is the preferred method to preserve spermatogonial stem cells prior to transplantation.

Which cryopreservation method better protects reproductive potential: the cryopreservation of a testicular cell suspension (TCS) or the cryopreservation of testicular tissue (TET)? Two cryopreservation strategies for spermatogonial stem cells (SSCs) were compared in a mouse model: cryopreservation as TET or as TCS. Evaluated outcomes were number of viable cells after thawing, number and length of donor-derived colonies after spermatogonial stem cell transplantation (SSCT), number of litters, litter size and number of donor-derived pups after mating. Compared with cryopreserving TCS, cryopreservation of TET resulted in significantly higher numbers of viable cells after thawing (TET: 13.4  ×  104 ± 7.2  ×  104 versus TCS: 8.2  ×  104 ± 2.7  ×  104; P = 0.0002), more (TET: 47.6 ± 19.2 versus TCS: 18.5 ± 13.0; P = 0.0039) and longer (TET: 5.2 ± 1.0 mm versus TCS: 2.7 ± 1.5 mm; P = 0.0016) donor-derived colonies, and more donor-derived pups per litter (TET: 2.2 ± 0.2 versus TCS: 0.5 ± 0.1; P = 0.0008). Cryopreservation of TET is the preferred method to cryopreserve SSCs prior to SSCT in a mouse model.