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

Hojeong Yu, Hoyeon Lee, Jiyong Cheong, Sang Won Woo, Juhyun Oh, Hyun Kyung Oh, Jae Hyun Lee, Hui Zheng, Cesar M. Castro, Yeong Eun Yoo, Min Gon Kim, Jinwoo Cheon, Ralph Weissleder, Hakho Lee

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


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 (n = 43) and controls (n = 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).

Original languageEnglish
Article numbereabe2352
JournalScience Translational Medicine
Issue number616
Publication statusPublished - 2021 Oct 20

Bibliographical note

Funding Information:
We acknowledge the following grant support: NIH R21DA049577, R01CA229777, R01CA239078, R01CA237500, DOD-W81XWH1910199, and DODW81XWH1910194 to Hakho Lee; R01CA204019 to R.W.; U01CA233360 to Hakho Lee and C.M.C.; and R01CA264363 to C.M.C.; Robert Wood Johnson Foundation and American Cancer Society to C.M.C.; MGH Scholar Fund to Hakho Lee; National Research Foundation (South Korea) 2017R1A2B3010816 to M.-G.K.; The Ministry of Trade, Industry and Energy (South Korea) 20012362 to Y.-E.Y.; and the Institute for Basic Science Grant (South Korea) IBS-R026-D1 to J. Cheon. We thank K. Chung (University of Illinois at Urbana-Champaign, IL, USA) and N. Jeong (Massachusetts General Hospital, MA, USA) for helpful discussion, M. Garlin (Massachusetts General Hospital) and S.-Y. Cheon (University of Southern California, CA, USA) for helpful discussion on graphic designs and illustrations, and K. Joyce for critically reading the manuscript.

Publisher Copyright:
Copyright © 2021 The Authors.

All Science Journal Classification (ASJC) codes

  • Medicine(all)


Dive into the research topics of 'A rapid assay provides on-site quantification of tetrahydrocannabinol in oral fluid'. Together they form a unique fingerprint.

Cite this