mdma powder/crystals have posed a threat to the health and well-being of a large number of people. Drug abuse affects the person socially, psychologically, and physically and has harmful effects on society. Urine drug testing kits are reliable, inexpensive, flexible, and accurate method of testing a person for drug use. Through this type of drug testing, it is possible to test many different drugs in different combinations. The five most commonly abused drugs are Marijuana, Methamphetamine, Ecstasy, Cocaine, and Heroin.
Specimen collection is important aspect of Urine drug testing method. Since integrity of specimen is of prime importance for the optimum validity of results of urine test. The container in which the urine is collected must be clean, unbreakable, and with no leaks. Any shortcomings in the specimen collection can damage the test results and invalidate it. It is necessary that collection of specimen should be done under supervision to avoid intentional adulteration and increases integrity of sample.
However, this procedure can also be embarrassing to individual. Addition of soaps, water from toilets in specimen by person can adulterate the specimen. Another process, which increases the effectiveness of urine testing method, is random sampling. It is a process where urine samples are taken in such a way that person does not know when the next specimen will be taken. Random sampling helps to increase the sensitivity of drug detection program.
The testing procedure followed by laboratories for drug detection in urine can be classified into two main categories-immunoassays and chromatography. The immunoassay procedure is used for screening of specimen while chromatography is done for confirmation. An Immunoassay is a biochemical test that measures the concentration of a substance in a biological liquid, typically serum or urine, using the reaction of an antibody or antibodies to its antigen (drug).
Two types of immunoassays used in urinalysis at this time–the radioimmunoassay (RIA) and enzyme immunoassay (EIA). In Radioimmunoassay (RIA), known amounts of radioactive-labeled drug are added to a urine sample with known amounts of antibodies. The mixture is then allowed to incubate, during which time the labeled drug and unlabeled drug compete for binding sites on the antibody.
The presence or absence of the drug is indicated by the amount of radioactivity found, since this is proportional to the amount of antigen (labeled drug) bound to the antibody. The commonly used EIA method for detection of drug is EMIT system. In EMIT assay, the label on the antigen is an enzyme (protein) that produces a chemical reaction for detection of drugs.
This detection is based on the competition between unlabeled drug and labeled drug for binding sites on the antibody. Chromatography is a method of analysis in which the various components in a biological specimen can be separated by a partitioning process. There are various chromatographic methods like Thin-Layer Chromatography, Gas-Liquid Chromatography, High-Performance Liquid Chromatography, Gas Chromatography/Mass Spectrometry.
Interpretation of Results:
Both negative and positive results have some meaning. A positive results means that the drug was present in the urine on condition that the entire drug test is performed nicely and results from laboratory are true. However, a positive result does not mean that the person was under influence of drug when specimen was collected. The authenticity of a positive result can be increased by repeated tests at regular intervals. Multiple positives results over a period show that the person is addicted.