Cannabinoids, Urine Screen UDRG4

• Urine specimens may be collected in plastic (i.e., polypropylene, polycarbonate, polyethylene) or glass containers. Some plastics, other than those listed, can adsorb certain drugs.
• If not analyzed immediately, specimens may be stored at room temperature at 15 - 25^o C for up to 7 days following collection. After 7 days, specimens should be stored frozen at <= -20^o C. Frozen specimens must be completely thawed and mixed thoroughly prior to analysis.
• Specimens with high turbidity should be centrifuged before analysis. The recommended pH range for urine specimens is 3.0 - 11.0. Adulteration of the urine specimen may cause erroneous results. If adulteration is suspected, obtain another specimen. Human urine specimens should be handled and treated as if they are potentially infectious.

Marijuana is a mixture of dried leaves and flowering tops of the plant Cannabis sativa L. The agents that produce the hallucinogenic and other biological effects of marijuana are called cannabinoids.

The cannabinoid, Delta⁹-tetrahydrocannabinol (Delta⁹-THC), is the principal psychoactive ingredient in marijuana and hashish. The compound Delta⁹-THC is quickly and effectively absorbed by inhalation or from the gastrointestinal tract and is almost completely metabolized by liver enzymes. Peak plasma levels of Delta⁹-THC occur within 10 minutes of inhalation, and approximately one hour after ingestion. Excretion of urinary metabolites and excretion by way of the feces begins within 72 hours after exposure. Concentration depends on the total amount of THC absorbed, frequency of abuse, rate of release from fatty tissue, and time of sample collection with respect to use. In chronic users, THC may accumulate in fatty tissue faster than it can be eliminated. This accumulation leads to longer detection times in urine samples for chronic users than for occasional users.

The Emit II Plus Cannabinoid Assay detects the major metabolite of Delta⁹-THC, 11-nor-Delta⁹-THC-9-carboxylic acid, in human urine. It also detects other Delta⁹-THC metabolites. The cutoff level for distinguishing positive from negative samples is 50 ng/mL.

Passive inhalation of marijuana smoke may produce positive results with low cutoff cannabinoid assays. Urine samples from nonsmokers can test positive for cannabinoid metabolites, but only after exposure to high concentrations of marijuana smoke in a small, unventilated area. Such extreme exposure conditions clearly are not typical of usual social situations. Positive results for samples containing other compound structurally unrelated to cannabinoids have not been observed.

Analytical Principle:  The Emit II Plus Cannabinoid Assay is a homogeneous enzyme immunoassay technique used for the analysis of specific compounds in human urine.

The Emit II Plus Cannabinoid Assay provides only a preliminary analytical test result. A more specific alternative chemical method must be used to obtain a confirmed analytical result. Gas chromatography/mass spectrometry (GC/MS) is the preferred confirmatory method but other chemical confirmation methods are available. Clinical consideration and professional judgment should be applied to any drug of abuse test result, particularly when preliminary positive results are used.