INTENDED USE

Accu-Stat™ THC-COC, a simple one-step immunoassay is intended for use in the qualitative detection of THC and cocaine metabolites in human urine with a cut-off at 300 ng/mL for cocaine.

The Accu-Stat™ THC-COC test provides a preliminary analytical result. A more specific alternative chemical method must be used in order to obtain a confirmed analytical result. Gas chromatography, mass spectrometry (GC/MS) is the preferred confirmatory method. Professional judgment should be applied to any drug of abuse test result, particularly when preliminary positive results are indicated. The newly packaged test for U.S. domestic market includes optional confirmation test at no additional charge.

SUMMARY AND PRINCIPLE OR PROCEDURES

THC (9-tetrahydrocannabinol) is the primary active ingredient in cannabinoids (marijuana). When ingested or smoked, it produces euphoric effects. Users have impairment of short term memory and THC use slows learning. Also, it may cause transient episodes of confusion, anxiety, or even frank toxic delirium. Long term, relatively heavy use may be associated with behavioral disorders. The peak effect of smoking THC occurs in 20-30 minutes and the duration is 90-120 minutes after one cigarette. Elevated levels of urinary metabolites are found within hours of exposure and remain detectable for 3-10 days after smoking. The main metabolite excreted in the urine is 11-nor-9-tetrahydrocannabinol-9-carboxylic acid.

Cocaine derived from the leaves of cocoa plant is a potent central nervous systems (CNS) stimulant and local anesthetic. Cocaine induces euphoria, confidence and a sense of increased energy in the user. These psychological effects are accompanied by increased heart rate, dilation of the pupils, fever, tremors, and sweating. Cocaine is used by smoking, intravenous or oral administration and is excreted in the urine primarily as benzolecgonine in a short time(1). Benzoylecgonine has a longer biological half-life (5-8 hours) than cocaine (0.5-1.5 hours) and can generally be detected for 24-60 hours after cocaine use or exposure.

Accu-Stat™ COC test uses solid-phase immunoassay technology for the qualitative detection of cocaine metabolite, benzoylecgonine, in human urine. This test is based on the competition for the limited antibodies between immobilized drug conjugate on the membrane and drug or drug metabolite which may be present in the urine being tested. In the test procedure, a sample of urine is placed in the sample well and is allowed to migrate upward. When the drug is present in the urine sample, it competes with drug conjugates which are immobilized on the membrane for the limited amount of antibodies present in the dye-antibody conjugate. When sufficient amount of drug or drug metabolite above the cut-off level is present, it will occupy all the antibody binding sites, and thus inhibit the binding of dye-antibodies to the drug conjugate preventing the formation of a line on the membrane. In addition to the Test line that may appear in the Test window, a Control line is added in the Control window to confirm the viability of the test. This Control line should always be seen if the test is conducted properly. Therefore, the presence of two lines, one in the Test window and the other in the Control window, indicates a negative result; while the absence of a line in the Test window indicates a positive result.

Accu-Stat™ THC-COC provides only a qualitative test results. To obtain a confirmed analytical results, more specific alternative methods such as gas chromatography/mass spectrometer (GC/MS) should be used. 

MATERIALS PROVIDED

PRECAUTIONS

STORAGE AND STABILITY

Accu-Stat™ THC-COC test kits should be stored at 4-30 C (40-86 F) in its original sealed pouch.

SPECIMEN COLLECTION AND PREPARATION

Approximately 4 drops of urine sample is required for each test. Fresh urine specimens do not require any special handling or pretreatment. If testing will not be performed immediately, specimens should be refrigerated (2-8 C) or frozen. Specimens should be brought to room temperature before testing.

TEST PROCEDURE

The test procedure consists of adding the urine sample to the Sample well of the device and watching for the appearance of colored lines in the Test window.  

TEST PROTOCOL

INTERPRETATION OF RESULTS

Negative Two Lines

• The appearance of two reddish-purple lines in the Test window and one in the Control window indicates a negative test result; ie., no cocaine or THC above the cut-off levels have been detected. The colored lines will appear within 1 to 3 minutes. The color of the Test lines may be weaker or stronger than that of the Control line.

Positive one line

• The appearance of only one reddish-purple line in the Control window and no distinct line in the Test window for COC indicates the result is positive for cocaine (i.e., the specimen contains more than 300 ng/ml of cocaine and its metabolites).

Confirmation Testing

Samples that are screened as negative do not need further examination. For a sample that is screened as positive, you should send it to our laboratory for further analysis to confirm the actual presence of the drug of abuse. Confirmation testing is performed using a combination of very sophisticated instrumentation and techniques known as gas chromatography/mass spectormetry (GCMS) which can accurately identify a drug of abuse. Confirmation testing should be performed on all preliminary positive screening results. Laboratory results can be retrieved within 5 to 7 business days from the time the sample is received in the laboratory. The test kit contains detailed instructions and all of lthe materials necessary for mailing the sample to our laboratory for testing. The instructions also describe how to obtain your confidential results. You need only identify yourself by the identification number provided.

Invalid

• A distinct colored line should always appear in the Control window. The test is invalid if no line forms in the Control window.

Limitations

User Quality Control

Control standards (for professional use) are not supplied with this kit; however, it is recommended that a control be tested as good laboratory testing practice. For information on how to obtain controls, contact Worldwide Medical’s Technical Services. Before using a new kit with patient specimens, positive and negative controls should be tested to confirm the test procedure, and to verify the tests produce the expected Q.C. results.

The Control line can be considered an internal control. A distinct reddish-purple Control line should always appear if the test procedure is performed properly and the test reagents are working. If the Control line does not appear, the test is invalid and a new test should be performed. If the problem persists, contact Worldwide Medical for technical assistance.

EXPECTED VALUES

Accu-Stat™ THC-COC is qualitative assay. The amount of drugs and metabolites present in the urine cannot be estimated by the assay. The assay results distinguish positive from negative samples. A positive result indicates the sample contains drug metabolites above the cut-off concentration.

PERFORMANCE CHARACTERISTICS

The National Institute on Drug Abuse has suggested that the screening cut-off for positive samples be 300 ng/ml for cocaine. Accu-Stat™ COC test has been shown to detect an average of 300 ng/ml or more for cocaine or its metabolites in urine. The accuracy of Accu-Stat™ COC was evaluated in comparison to a commercially available immunoassay at a cut-off of 300 ng/ml. A total of 1021 samples were tested by both procedures with 97% agreement.

In a separate study, Accu-Stat™ COC was evaluated against specimens confirmed as positive by GC/MS. Of 78 samples confirmed as positive, 77 samples were positive when tested with Accu-Stat™ for 99% agreement.

SPECIFICITY

Accu-Stat™ COC test detects the cocaine metabolite, benzoylecgonine. The following table lists compounds that cross react in this test. The results are expressed as the concentration required to produce a positive result.
 

REFERENCES