Of all the men willing to donate their sperm, only about 5% of them meet the preconditions set to be a sperm donor. Before they can donate their sperm, men are put through an intense scrutiny, wherein they are questioned about their family backgrounds, apart from running medical tests on them.
The doctors also test their semen for sperm count, its mobility as well as its morphology. They are tested for any genetic diseases and for infectious diseases such as HIV, Hepatitis B, and Hepatitis C. After the doctors decide that a particular candidate is fit to donate his sperm, the donation process begins.
Under the actual process of sperm donation, the man is led into a private room where he masturbates into a sterile container. The semen thus collected, is then put into cryopreservative solution, filled into vials and stored in liquid nitrogen. Men are usually paid $40-100 for a sperm donation. One man is allowed to sire about 10 children in the process.