Stanford researchers develop marijuana saliva test based off cancer screening technology

PALO ALTO, California – Researchers at Stanford University say they have developed one of the first possible roadside tests to find out whether people are driving under the influence of marijuana.

Judicial and law enforcement agencies have for years tried to devise a plan for testing a driver’s impairment since the psychoactive ingredient in marijuana can stay active in a person’s cells for up to 45 days and breaks down in the body differently than alcohol.

The researchers at Stanford believe they may have the answer with their “potalyzer,” which the university says can quickly detect the presence of THC in a person’s saliva and measure its concentration levels in a few minutes.

The device uses magnetic biosensors, originally used in cancer screenings, that can detect THC molecules.

Field officers could theoretically swab a person’s cheek and receive the results of the test on a phone or computer in as little as three minutes, the researchers say.

Colorado drivers can be charged with driving under the influence if the amount of THC in their blood is at or above five nanograms per milliliter of blood.

The Stanford research model would be able to detect between 0 and 50 nanograms per milliliter of saliva.

Colorado State Patrol is in the midst of a three-year pilot program testing devices similar to the one developed at Stanford.

Over the past year, at least 150 troopers started using one of five tests that look at a driver’s saliva as well. CSP says it wants to collect several years’ worth of data before choosing a specific device.

More information on the Stanford model can be found here.