QUICK TEST TRACKS DOWN DRUG ABUSERS

Police, sports regulators and employers will soon have a new tool to
aid their efforts to monitor drug abuse: a hand-held unit called the
Cozart RapiScan. The device simultaneously tests a sample of saliva
for a host of substances such as cannabis, cocaine, amphetamines,
ecstasy, opiates such as heroin and morphine, and benzodiazepines.

A swab of saliva is placed inside a cartridge containing a strip of
nitrocellulose membrane divided into a number of zones. Each zone is
laced with different types of antibodies and receptors that are
sensitive to a specific drug. As the strip absorbs clean saliva, the
antibodies float free and bind to their receptors, turning the
membrane pink. However, if the saliva contains certain drugs, the
antibodies have to compete with the drugs in order to bind to the
membrane in their respective zonesF0so there is no colour change.

RapiScan reads colour changes electronically so judgments are not
subjective. And the maker claims the system can detect nanogram
quantities of drugs using just a millilitre of saliva. "This is as
reliable as a urine test but much faster, with a result appearing in
five to 12 minutes. It's as easy as reading a pregnancy test," says a
spokeswoman for Cozart, the Oxfordshire-based company which makes the
device.

Police in Australia are now using the RapiScan to see if there is any
connection between road accidents and certain illegal drugs. Cozart
says it has also attracted interest from the British prison service
and the military.