As highlighted by various dop- ing scandals in the world of sports, drug abuse can appear anywhere. Current methods for testing for drug abuse are cumbersome, nonspecific, and lengthy.

A group of Finnish researchers at the Technical Research Centre of Finland has developed a quick, inexpensive and highly specific one-step drug test.

FINDING A BETTER WAY

As part of the Tekes Diagnostics 2000 technology programme, Dr Kristina Takkinen, group manager of the immunotechnology group of the Technical Research Centre of Finland’s biotechnology group, in Espoo, and her team were bent on finding a way to improve drug testing using anti- bodies.

“The normal methods for drug testing start with a simple dip stick that changes colour when detecting a certain drug, such as morphine, in a sample,” says Takkinen.

But the dip stick is not specific enough to detect similar drugs that are not illegal, such as codeine, and, therefore, requires a second, more specific and lenghty step with more complicated machinery.

“We knew that a combination of antibodies could be much more specific,” says Dr Timo Pulli, at the time a research scientist on the project.

By using advanced biotechnology, the team was able to create a two-antibody system that was highly specific for morphine, with no cross reaction with similar molecules, such as codeine, which is found in cough syrup.

ENTER CLEVER CHEMISTRY

While the antibodies provided the specificity that was already much better than a dip stick, the team had to use clever chemistry to speed up and simplify the test, using a technique called fluorescence energy transfer (Fret).

By using Fret, the drug test only required the antibodies, the sample, and a fluorescence detector. The antibodies, attached to fluo- rescent molecules, are mixed with the sample and, after two minutes to allow for the anti- bodies to bind the morphine, the mixture is measured with a fluorescent- detection system.

Not only was this test faster and simpler than a dip-stick test, but it was also much more sensitive, even with large amounts of similar molecules in the mixture that would have confounded a dip-stick test.

LOOKING TO CONTINUE

Both Takkinen and Pulli were driven by their progress in solving the specificity issue to create an easier and faster drug test.

There is still more they want to do. Morphine was the first drug used to test the system. They would like to create a panel of antibodies to detect multiple drugs in a single sample with a single analysis. Also, one of their goals is to create a portable system to carry out their new drug test, to improve the response times for drug testing in time-sensitive situations, such as sporting events or police activity.

The group continues the development of this system as part of Tekes’ FinnWell Future Healthcare Technology programme.

To subscribe to Engineering News's print magazine email subscriptions@creamermedia.co.za or buy now.