“When I developed this method for preserving mouse sperm by freeze drying it on a sheet, I thought that it should be able to be mailed on a postcard and so when offspring were actually born after being mailed, I was very impressed,” said the University of Yamanashi’s Professor Daiyu Ito, first author of the iScience paper.
“The postcard strategy was easier and cheaper compared to any other method. We think the sperm never expected that the day would come when they would be in the mailbox.”
Ito belongs to the laboratory of mouse-cloning expert Professor Teruhiku Wakayama. The group had previously become the first to freeze dry and preserve mammalian sperm, which was sent to the ISS for studies into the effect of space radiation on young mice. The semen samples were originally preserved in a glass ampule (a small vial) which were prone to breaking and thus ruining the contents. This forced the researchers to use cushions to prevent breakage during transport...