Scientists Develop On-Site Test for Cannabis Use Similar To A Breathalyzer

Researchers may be closer to developing the equivalent of a breathalyzer for detecting marijuana in a person's system, according to an article published this week in the journal Science Translational Medicine.

At the moment, the gold standard for detecting marijuana usage is to measure THC, the active ingredient in cannabis, in the blood or urine. But those tests can take days to process and unlike alcohol, THC can linger in the bloodstream for days, said Hakho Lee, Ph.D., director of the Biomedical Engineering Program at Harvard University and senior author of the new study, as reported per the AAAS.

There are some existing saliva tests for THC, but they are limited by issues like slow processing time or giving "binary" results (yes/no). To enable quick on-site THC quantification, the scientists behind the research developed a rapid assay for oral THC analysis called EPOCH, which is similar to a breathalyzer and allows assay completion within 5 minutes. 

"With marijuana becoming more accessible, it is important for public safety to have an objective way to tell whether a person is under its influence,” Lee said.

The initial testing accurately picked up THC in saliva samples from all users of the plant within about 3 minutes. The researchers eventually plan to expand their test to detect drugs, such as oxycodone and other synthetic opioids.

"Since our device is a platform technology, we could readily detect different targets by switching capture [molecules]," Lee added.