New tests may catch bicyclers on dope.

The 1998 Tour de France was a bust. Seven people--one rider and six support crew--were suspected of using or providing riders with a synthetic version of erythropoietin (EPO), a hormone that stimulates production of red blood cells. The authorities couldn't confirm the suspicions, however, since no test could distinguish synthetic EPO from natural EPO in blood or urine.

French researchers Francoise Lasne and Jacques de Ceaurriz of the National Anti-Doping Laboratory in Chatenay-Malabry have now devised a urine test for the drug. Using a technique based on pH measurements, the researchers are able to differentiate between natural and synthetic EPO.

Testing 102 stored urine samples from participants in the 1998 race, they found that the 14 samples with the highest amounts of EPO all tested positive for the synthetic form of the hormone. The results appear in the June 8 NATURE.

In the June HAEMATOLOGICA, Australian researchers describe a new blood test that also detects synthetic EPO.

Physicians suspect that dozens or even hundreds of athletes have died of heart attacks or stroke caused by synthetic EPO, says Arnie Baker, a physician and cycling coach in San Diego. Without a test, EPO abuse came to light "only when people broke the so-called code of silence," he says.