Marijuana Drug Testing Instructions - THC Cassette Test

INTRODUCTION

Marijuana is a major drug of abuse. After smoking or oral administration, the major psychoactive compound, tetrahydrocannabinol (THC), is extensively metabolized before excretion. The presence of tetrahydrocannabinol acid or the cannabinoid metabolite in urine is an indication of marijuana use. The excretion half-life of cannabinoid metabolites in urine, estimated by different techniques, ranges from one to ten days. For a positive initial immunoassay result, a cut-off value of 50 ng/mL total cannabinoid metabolites is required by the mandatory reference guidelines from the U.S. Department of Health and Human Services.

The One Step Marijuana (THC) Test is a fast, qualitative, and visually read immunoassay for screening urine samples without the use of an instrument. The method employs a unique monoclonal antibody to selectively identify THC metabolites in the urine test sample with a high degree of sensitivity. The sensitivity of IND One Step Marijuana Test is set at a concentration of 50 ng/mL 11-nor-N9- tetrahydrocannabinol-9-carboxylic acid. This product is not intended to monitor drug levels, but only to screen urine samples for the presence of cannabinoid metabolite.

Note: This test provides only a preliminary analytical result which should be confirmed by a more specific method. Gas chromatography/ mass spectrometry (GC/MS) has been established as the preferred confirmatory method by the National Institute on Drug Abuse (NIDA). Clinical consideration and professional judgment should be applied to any drug of abuse test result, particularly when preliminary positive results are indicated.

PRINCIPLE OF THE TEST

The One Step Test for THC is based on the principle of a competitive inhibition immunoassay, in which a chemically labeled drug (drug conjugate) competes with the drug that may be present in urine for a limited number of antibody binding sites. The test device consists of a membrane strip, which is pre-coated with THC-BSA conjugate on the test band region, and a colored anti-THC monoclonal antibodycolloid gold conjugate pad, which is placed at the end of the membrane.

In the absence of the drug in the urine, the colored antibody-colloid gold conjugate moves with the sample fluid by capillary action along the membrane until it reaches the immobilized drug conjugate in the test band region. At this point, the antibody-colloid gold conjugate reacts with the pre-coated drug conjugate to produce a visible red colored line as the antibodies form complexes with the drug conjugate. The formation of a visible color line on the test band region will indicate the urine sample is tested negative for THC.

When the drug is present in the urine, the drug/metabolite antigen will compete with the drug conjugate coated in the test band region for the limited antibody sites. When a sufficient concentration of drug is present, it will fill the limited antibody binding sites, and thus preventing the attachment of the colored antibody-colloid gold conjugate to the drug conjugates pre-coated in the test band region. An absence of the color band in the test region indicates a positive result.

A control band with a different antigen/antibody reaction is also added to the membrane strip to indicate that the test is performed properly. This control line should always be seen. A negative urine sample produces two distinct color bands. A positive sample produces only one color band in the control zone.

SPECIMEN COLLECTION

A fresh urine specimen should be used, no special pre-treatment is necessary. The specimen may be refrigerated (2-8oC) and stored up to 2 days, or frozen (-20oC or below) prior to assaying. If samples are refrigerated they should be brought to room temperature before testing.

TEST PROCEDURE

1. Bring the sealed foil pouch and urine sample to room temperature.
2. Open the foil pouch at the notch and remove the test device from the pouch.
3. Using the sample pipette, withdraw the urine sample from the specimen cup.
4. Add 4 drops into the sample well. (Make sure that the sample pipette is held vertically, and the complete number of drops is added to the sample well).
5. Read results in 10 minutes. Results obtained after more than 10 minutes are not considered valid.

INTERPRETATION OF RESULTS

Negative: In addition to one pink colored control (C) line in the control region, a distinct pink colored line will also appear in the patient test (T) region. The color intensity of the test line may be weaker or stronger than that of the control line.

Positive: Only one colored line appears in the control (C) region. No apparent line in the patient test (T) region. This indicates the presence of a drug/metabolite at a level of 50 ng/mL or above.

Invalid: No line appears in the control zone “C”. An invalid result may be due to improper testing procedures or deterioration of the kit components. Repeat the assay sequence using a new device.

Note: A faint line on the test region means that the THC in sample is near the cut-off level for the test. These samples should be re-tested or confirmed with a more specific method before a clinical determination is made.

STORAGE AND STABILITY

The test kit can be stored at temperatures between 2 to 30°C in the sealed pouch to the date of expiration. The test kit should be kept away from direct sunlight, moisture and heat.

PRECAUTION

1. For in vitro diagnostic use only.
2. Do not use test kit beyond the expiry date.
3. The test device should not be reused.
4. Urine specimens may be infectious; insure proper handling and dispose of all used reaction devices into a biohazard container.