After the sample has been washed, analyzed, and separated into multiple vials, lab scientists add cryoprotectant, a solution that prevents ice from forming in the sperm. Then, the sperm is brought down to a very low temperature — -196ºC — using liquid nitrogen in a “slow freeze” technique.
We reserve a small portion of your sample to freeze and then thaw to conduct a post-thaw analysis, also known as a post-thaw motility check. This test ensures the sperm survive freezing and give you a more accurate estimate of your total motile sperm count when you want to use the sample. Legacy is the only at-home sperm freezing option that provides post-thaw analysis.