A simple method for cryopreservation of human sperm.

A simple method of cryopreservation of human sperm is discussed. Fifteen randomly collected samples were frozen and assessed after storage in liquid nitrogen. The mean recovery rate was 77% (range 62-91%) with no significant deterioration after 4 weeks' storage. The cryopreserved sperm is used in an artificial insemination by donor clinic and also sent to distant centres in the RSA and neighbouring countries. The method is also used for the cryopreservation of specimens of the sperm of patients undergoing vasectomy or radiotherapy, and in the Groote Schuur Hospital in vitro fertilization programme. Modification of the method will also allow human embryos to be frozen.