Rapid drug tests commonly refer to in-house drug screening paraphernalia that has become increasingly popular in recent years, with growing numbers of employers adopting toxicology screening processes during hiring and reviewing procedures. These are primarily comprised of lateral flow immunoassays, which introduce biological liquid analytes to a conjugated drug via a soluble sample bed. The drug binds to antigens present in the sample, and the presence of the drug is registered as a chromatic response by test lines on the immunosorbent membrane. Such rapid drug tests can detect the presence of given antigens in biological samples within minutes.
Speed and convenience are the primary attraction to rapid drug tests such as lateral flow immunoassays, yet they are typically used as a preliminary testing methodology rather than for definitive diagnoses. This is due to the increased likelihood of false results as opposed to more robust laboratory testing methods such as enzyme immunoassay (EIA or ELISA) testing options.
But how accurate are rapid drug tests? This article will explore the accuracy of immunoassay tests in more detail:
The Limitations of Rapid Drug Tests
Rapid drug tests currently available on the market are typically limited to testing urine samples, but they can determine the presence of multiple antigens from such a sample. This is achieved through a visible chromatic response. The chromatic response is pre-determined by drug cut-off levels that separate positive from negative results based on the concentration of drug present in the analyte. For instance, rapid drug tests for the detection of cannabis in a urine sample may have cut-off levels as sensitive as 20 ng/ml, which will render a positive result if the concentration of THC is above that limit.
For this reason, and the fact that they are not quantitative, rapid drug tests are often termed presumptive, and any inconsistencies in immunoassay tests should be referred to laboratory testing for confirmation and deeper analysis. However, they are a critical component in the urinary drug testing system and are increasingly utilized as the first step in robust toxicology screening processes.
Rapid Drug Tests with Pyxis Laboratories
Pyxis Laboratories is a leading supplier of drug conjugates and reagents for numerous laboratory testing and screening products. We synthesize custom conjugates for clients across the world, with ready-to-order regents, including:
- Alcohol such as, ethyl glucuronide-BSA (EtG-BSA);
- Amphetamines such as, Amphetamine-BSA, Methamphetamine-BSA, methcathinone-BSA, MDMA-BSA, MDPV-BSA, Mephedrone-BSA and Methylphenidate-BSA (Ritalin-BSA);
- Benzodiazepines, such as Oxazepam-BSA and Clonazepam-BSA;
- Cannabinoids such us, delta-8-THC-BSA, delta-9-THC-BSA; and synthetic cannabinoids such as, JWH-018-BSA, ABpinaca-BSA, UR144-BSA;
- Cocaine, such as BZEG-BSA;
- Hallucinogens/Anesthetics such as, Ketamine-BSA and PCP-BSA;
- Nicotinic such as, Cotinine-BSA;
- Opioids such as, Buprenorphine-BSA, Fentanyl-BSA, Methadone-BSA, Morphine-BSA, Oxycodone-BSA, Propoxyphene-BSA and others such as Chloramphenicol-BSA, Gabapentin-BSA and N-acetyl glucosamine-BSA (NAG-BSA).