MODEL RELEASED. IVF sperm bank. Technician removing a holder containing human sperm cells from a cryogenic storage tank. The sperm will be used in in vitro fertilisation (IVF). The sperm are frozen in liquid nitrogen at -196 degrees Celsius. After a sample is removed and thawed, the healthy sperm cells are introduced to egg cells (ova) harvested from the intended mother. This is done in a laboratory. Successfully fertilised eggs are then implanted in the woman's uterus, and a normal pregnancy can follow. IVF is used when a couple cannot conceive naturally. Storage of frozen sperm can preserve a man's ability to have children if he becomes infertile.