Like embryos are freezing for later use, now sperm are also frozen for later use or research. Sperm freezing is the procedure of storing the fresh sperm in storing tank containing liquid nitrogen.
This procedure comes in practice when it was noticed that the number of infertile men increases and they are progressively infertile, it helps various couples where male partner suffer infertility issues like low sperm count, poor quality sperm and so on.
Men donate or wanting to store their sperm for potential future use, and the procedure is as simple as that, one just need to Google (search) a fertility clinic that supports sperm freezing procedure, and fill a consent form which includes some of your rights on your sperm usage, and then you need to provide a fresh semen sample at the clinic for storing procedure. Before donating sperm, you will be screened to ensure the inherited diseases, including HIV and Hepatitis B and C.
The medium used for freezing contains cryoprotectants (glycerol) that help to remove water from the cells being frozen. In the case of low sperm count, stored sperm can be used for IVF, ICSI, where one sperm is directly injected into the egg. Generally sperm cells have been stored and thawed successfully for more than 40 years.