How it works: a look at the retests of Olympic drug samples (Yahoo Sports)

Inside a non-descript concrete building in a Swiss parking lot lies evidence that could take down dozens of Olympic athletes. The anti-doping laboratory in Lausanne holds the stored urine and blood samples from the 2008 and 2012 Olympics that are being retested with improved techniques to catch drug cheats who escaped detection at the time and to keep them out of this summer’s games in Rio de Janeiro. Results on tests of 250 samples from the 2012 London Olympics will be known soon.