But the test, now widely used and even patented in part by the French laboratory, has limitations and ambiguities, a number of prominent scientists said, largely because injected EPO is a near carbon copy of a molecule that naturally appears in the body. Even as the World Anti-Doping Agency, known as WADA, has adopted and repeatedly defended the French test, it has been funding projects to improve it.
"This is not like a pregnancy test, where you are either pregnant or you're not," said Dr. Nicolle Packer, executive vice president of Proteome Systems in Sydney, which has one of the research grants. "It has to be prepared carefully and interpreted by an expert, who can mostly call it, I believe," she said in a tele phone interview. "But it is definitely skill-based, and that is why WADA is looking for a more clear-cut test."
Just last month, because of the uncertainty, Belgian authorities overturned a competition ban on a champion triathlete, Rutger Beke.
Scientific experts had raised questions about the reliability of two urine specimens that tested positive for EPO at the Belgian anti-doping laboratory.
In studies, some athletes will erroneously test positive for EPO after strenuous exercise, said Joris Delanghe, a noted chemistry professor at Ghent University in Belgium, who defended Beke.
How the issue plays out in these two hotly contested cases may determine how and when the test can be used, particularly to sanction athletes [....]
To distinguish recombinant EPO from the natural substance, the scientists used a technique that did not rely heavily, as before, on more straightforward chemical tests.
To test for EPO, a preparation of urine is placed on the edge of a blotter and then subjected to the pull of an electrical field. The sugar-covered proteins slowly migrate across the blotter, leaving deposits in certain patterns that resemble a tiger's stripes.
Some bands are more associated with recombinant EPO, some more with the natural substance. But there is considerable overlap as well. Scientists assess the patterns and intensity of the bands.
The report, which was recently removed from WADA's Web site, found that naturally occurring proteins in the urine of athletes could register in the band associated with injected EPO and that the patterns could be distorted if the urine was not properly stored.
"I'm not condemning the test, but there are problems," Delanghe said.
Pound said that WADA was constantly working to refine its tests.
Gmeiner's lab has developed software that would help quantify the pattern of bands and Proteome Systems has developed a new test, described for the first time in the scientific literature last month, which applies electrical fields in two dimensions instead of one, giving more definitive separation of natural and illegal EPO.
It is unlikely that Armstrong will face sanctions based on the French lab's new test. To prove that the test as run was scientifically valid, scientists would have to be able to reproduce it and to show that a control sample of synthetic EPO frozen for many years would give a similar banding pattern, said Packer of Proteome Systems.
"If I were Lance Armstrong, that's what I would insist on in court," Packer said.
