COME the next Olympics in 2004, it may be possible to screen all the athletes
for drugs, not just a few picked out for random tests. A new lab-on-a-chip
detection system could test thousands of samples in hours, probing each for
dozens of illegal substances.
The system could remove the stigma and unfairness of being singled out for
testing, while the certainty of being screened should serve as a deterrent for
would-be cheats. 鈥淚t would create a level playing field for everyone,鈥� says
Roisin Molloy of Randox Laboratories, the company which developed the Evidence
system in Crumlin, County Antrim. 鈥淭he athletes would love that,鈥� says a
spokeswoman for the anti-doping team at UK Athletics, the governing body for the
sport in Britain.
The system relies on established antibody screening technology, but Randox鈥檚
scientists have adapted it for a silicon 鈥渂iochip鈥� 1 centimetre across that
tests for up to 25 drugs at once.
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Antibodies that trap specific drugs and their metabolites鈥攖he
by-products of their breakdown in the body鈥攁re attached to the surface of
the chip in an array of 25 spots. So when a single urine sample is spread across
the chip, the system tests it simultaneously for all 25 substances.
A fluorescent 鈥渢ag鈥� substance is then washed over the chip. It binds to any
antibody that has captured its target, then emits light. The amount of light
given off by each spot shows how much of each substance is present. 鈥淚t means
you can detect the parent compound and the metabolites simultaneously,鈥� says
Molloy.
The system is capable of carrying out tests at the rate of one per second, so
officials could test every athlete at a meeting. Molloy envisages that it will
be used as an initial screen. 鈥淭hey鈥檇 have to do confirmatory analyses on any
suspect results,鈥� she says.
At present, the biochip includes common drugs of abuse in sport such as the
anabolic steroids nortestosterone and trenbolone, but Randox is experimenting
with others.
David Cowan, director of the Drug Control Centre at King鈥檚 College, London,
which is accredited by the International Olympic Committee, says such a system
would 鈥済reatly assist鈥� in pre-screening. 鈥淚t would be exciting if we could test
the whole field for the full range of substances,鈥� he says.
The tests will have to be reliable. 鈥淲hat鈥檚 critical would be false
positives,鈥� says Michele Verroken, head of the anti-doping programme at the
government-funded body UK Sport. 鈥淚f we get it wrong, we鈥檇 be sued off the
辫濒补苍别迟.鈥�
Sample collection could also be a problem, says the UK Athletics spokeswoman,
as nerves can make it difficult for athletes to urinate on demand. The best
solution, she says, would be to develop chips that analyse saliva, which is
easier to collect. Molloy says that Randox is working on this.
The company will present its biochip system next month at the annual
conference of the British Association of Sport and Exercise Sciences in Newport,
Gwent.