Cotinine Assay Rapidly Confirms Nonsmoking Status

However, until recently it has not been easy to prove diagnostically that an individual was a non-smoker.

Toward this end, the British biotech company GFC Diagnostics (Bicester, United Kingdom) has introduced the Saliva SmokeScreen test. The test detects cotinine, a breakdown product of nicotine. Cotinine has an in vivo half-life of approximately 20 hours, and is typically detectable for several days (up to one week) after the use of tobacco. The level of cotinine in the blood is proportionate to the amount of exposure to tobacco smoke, so it is a valuable indicator of tobacco smoke exposure. The newly improved Saliva SmokeScreen assay is more sensitive and specific than its previous version, being reported at 90% and 98% respectively, with an accuracy of 94%.

To test for nicotine exposure the user places the test swab in the mouth to absorb 1.5 mL of saliva. The swab is removed from the mouth, placed inside the plastic collector, and pushed against the grid half way down. This procedure squeezes the saliva into the bottom of the collector. The presence of cotinine causes a color change that is visible after one minute. The optimal time to read the result is six minutes. If read before five minutes, the result will be positive, but less than the correct result. After six minutes, it will be more than the true result.

The Saliva SmokeScreen test has been certified as a tool in a British health insurer's program to verify nonsmoking in their policy holders, so they can qualify for its unique nonsmoker cash back reward. Dr. Graham Cope, technical director at GFC Diagnostics and an honorary senior research fellow at the University of Birmingham (United Kingdom), said, "Smoking is an important risk factor for many chronic diseases, such as respiratory diseases, cardiovascular disease, and diabetes. It also causes blood pressure to rise and is linked with high cholesterol levels. We are pleased the SmokeScreen test has been chosen as the means to monitor smoking in this program."

Related Links:
GFC Diagnostics
University of Birmingham