Sperm magnet to help infertile men
10:23 10 January 2005
Exclusive from New Scientist Print Edition
Rachel Nowak, Melbourne
A sperm-sorting machine could soon allow fertility clinics to filter out sperm that have a type of DNA damage associated with infertility and a heightened risk of childhood cancers in offspring.
Mechanised sorting should be particularly useful when a would-be father is older, or is a heavy smoker or has been exposed to pollution in the workplace - all factors that increase this type of DNA damage.
When attempting IVF with sperm from men with fertility problems, clinics usually centrifuge the semen to increase the concentration of the densest sperm cells, which tend to be the healthier ones. For certain fertility treatments, technicians also try to pick the healthiest-looking sperm, for example, those with regular, ovoid heads.
But the centrifuge alone takes at least 45 minutes to sort sperm, which is a long time when processing hundreds of samples in a busy clinic, and neither technique can spot sperm that are free of DNA damage. Enter the new sperm sorter, developed in Australia by John Aitken and Chris Ainsworth at the University of Newcastle in New South Wales, alongside commercial partner Life Therapeutics of Sydney.
20-day voyage
The sorter is based on the principle that sperm with the most negatively charged membranes have the least DNA damage. Aitken is not sure why this is the case, but he speculates that it may simply be that these sperm are more likely to have matured normally. ...cont'd
http://www.newscientist.com/article.ns?id=dn6842