Send to

Choose Destination
Forensic Sci Criminol. 2018;3(1). doi: 10.15761/FSC.1000125. Epub 2018 Mar 28.

Multi-laboratory validation of a Δ9-tetrahydrocannabinol LC-MS/MS test kit designed for quantifying THC and marijuana metabolites in blood.

Author information

PinPoint Testing, LLC, Little Rock, Arkansas, 72202, USA.
Ohio State Highway Patrol Crime Laboratory, Columbus, Ohio, 43209, USA.
Idaho State Police Forensic Services, Meridian, Idaho, 83642, USA.
Kentucky State Police Central Forensics Laboratory, Frankfort, Kentucky, 40601, USA.
West Virginia State Police Forensic Laboratory, South Charleston, West Virginia, 25309, USA.
Arkansas State Crime Laboratory, Little Rock, Arkansas,72205, USA.
Wadsworth Center, Department of Health, Albany, New York, 12201, USA.
Biotage GB Limited, Distribution way, Cardiff, CF82 7TS, UK.
Biostatistics Program, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205, USA.
Department of Pharmacology & Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205, USA.


Marijuana legalization has increased the demand for testing of Δ9-tetrahydrocannabinol (THC) and THC metabolites. The THC ToxBox® test kit (THC ToxBox®) is commercially available and supports high-throughput LC-MS/MS analytical methods designed to quantify low levels of THC and THC metabolites in blood. The purpose of this study is to determine if this new test kit meets the rigors of laboratory accreditation and produces equivalent results across six states- and locally-funded laboratories. Each laboratory followed internal method validation procedures established for their clinical (CLIA) or international (ISO17025) accreditation program. Test performance indicators included accuracy, precision, measurement of uncertainty, calibration models, reportable range, sensitivity, specificity, carryover, interference, ion suppression/enhancement and analyte stability. Analytes and interferents were resolved within the 6-min analytical runtime, and the 48-well plate pre-manufactured with calibrators, second source quality control material, and internal standards at precise concentrations allowed for simple and consistent sample preparation in less than one hour. Every laboratory successfully validated test kit procedures for forensic use. Differences in sensitivity were generally associated with the use of older equipment. Statistical analysis of results spanning reportable ranges show that laboratories with different instrument platforms produce equivalent results at levels sufficiently low enough to support per se limit testing of THC and THC metabolites (1-5 ng/mL). THC ToxBox® represents a viable option for state- and locally-funded laboratories charged with investigating impaired driving cases involving marijuana use.

Conflict of interest statement

Conflict of interest disclosure Amy Patton, Jeffery Moran, and Gregory Endres are employees and/or owners of PinPoint Testing, LLC. PinPoint Testing, LLC owns the trademark for ToxBox®. Lee Williams is an employee of Biotage, LLC. PinPoint Testing, LLC and Biotage, LLC products were used as part of this study.

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center