It may also be used to decrease the risk of HIV transmission by an HIV-positive male, in which case the washed sperm is injected into a female using an artificial insemination technique.
Once the fastest sperm have been isolated, before using them for artificial insemination or in vitro fertilization, it is important to confirm the absence of HIV virus in the sample.
In normal semen samples, centrifugation causes no more DNA damage to spermatozoa than a direct swim-up technique.
One Italian study from 2005 of 567 serodiscordant couples treated with washed sperm resulted in no horizontal (to the woman) or vertical (to the child) HIV seroconversion.
Starting in the mid-1990s the technique was used to help HIV discordant couples conceive without passing the virus from the father to the mother or child.