Cryopreservation of sperm
The cryopreservation of sperm in livestock, especially cattle, has a long history of half a century and has been put to practical use. However, in the last twenty years, sperm freezing has finally reached a practical level in mice, the most commonly used laboratory animal.
There are many strains of mice, including inbred and mutant strains, and transgenic/knockout strains, which contribute to medical research. In some strains of mice, in vitro fertilization may not be successful due to poor sperm viability, but it is possible to produce offspring through ICSI.