A rapid assay provides on-site quantification of tetrahydrocannabinol in oral fluid

• Published in: Science translational medicine Vol. 13; no. 616; p. eabe2352
• Main Authors: Yu, Hojeong, Lee, Hoyeon, Cheong, Jiyong, Woo, Sang Won, Oh, Juhyun, Oh, Hyun-Kyung, Lee, Jae-Hyun, Zheng, Hui, Castro, Cesar M, Yoo, Yeong-Eun, Kim, Min-Gon, Cheon, Jinwoo, Weissleder, Ralph, Lee, Hakho
• Format: Journal Article
• Language: English
• Published: United States 20.10.2021
• Subjects: Biological Assay; Dronabinol; Saliva; Substance Abuse Detection; Tandem Mass Spectrometry
• ISSN: 1946-6242
• DOI: 10.1126/SCITRANSLMED.ABE2352

Tetrahydrocannabinol (THC), the primary psychoactive ingredient of cannabis, impairs cognitive and motor function in a concentration-dependent fashion. Drug testing is commonly performed for employment and law enforcement purposes; however, available tests produce low-sensitive binary results (lateral flow assays) or have long turnaround (gas chromatography–mass spectrometry). To enable on-site THC quantification in minutes, we developed a rapid assay for oral THC analysis called EPOCH (express probe for on-site cannabis inhalation). EPOCH features distinctive sensor design such as a radial membrane and transmission optics, all contained in a compact cartridge. This integrated approach permitted assay completion within 5 min with a detection limit of 0.17 ng/ml THC, which is below the regulatory guideline (1 ng/ml). As a proof of concept for field testing, we applied EPOCH to assess oral fluid samples from cannabis users ( = 43) and controls ( = 43). EPOCH detected oral THC in all specimens from cannabis smokers (median concentration, 478 ng/ml) and THC-infused food consumers. Longitudinal monitoring showed a fast drop in THC concentrations within the first 6 hours of cannabis smoking (half-life, 1.4 hours).