Comparative characteristics of spermatozoa harvested and cryopreserved in culture and cryoprotectant media with or without donor serum proteins

The objectives of this study is to evaluate the efficacy of protein-free media in the preparation, holding and crypreservation of spermatazoa for use in ART. Normozoospermic semen samples (N=71) were used to compare the effects of media on the survival and quality of spermatozoa when washed and cultured with different media with and without added proteins at 4°C, 15°C, 22°C and 37°C for 0, 4-7 and 24h. Survival and quality of spermatozoa were assessed after freeze-thaw with synthetic cryoprotectant with and without proteins. Ethics/IRB approval was obtained (Ref. 1073.52). Spermatozoa parameters were similar in all media after washing and culture for 24h. Post-thaw survival and quality of spermatozoa was not significantly different 24h after thawing of samples frozen in all cryoprotectant medium. In conclusion synthetic protein-free culture and cryoprotectant media are equal in efficacy to protein-containing media in culture and cryopreservation of spermatozoa . Use of these synthetic media are anticipated to significantly reduce the risk, potentially associated with conventional protein-containing media, of transmission of disease and possibly harmful undeclared proteins to the patient, baby and the healtcare worker. Synthetic media also ensure consistency of quality between batches of media.