Urine drug testing is typically tested for Illicit and Opioid drugs such as Marijuana, Cocaine, Opiates, PCP and Amphetamines and also some test for Methadone and Benzodiazepines. The level of drug or its metabolites is not predictive of when the drug was taken or how much the patient consumed. It is used as a confirmatory report indicating the presence of the parent drug or its metabolites. A drug, if present in the urine specimen below its cut-off concentration, will not saturate the binding sites of its specific antibody. The antibody will then react with the drug-protein and a visible colored line will show up in the test line region of the specific drug strip.
The urine sample goes through a specified "chain of custody" to ensure that it is not tampered with or invalidated through lab or employee error.
There are two types of urine drug screens. the first, called the immunoassay (rapid screen) gives results quickly. However, the one drawback is it does not pick up on all opioids (narcotics) and sometimes gives a false positive for drugs but not drugs have been taken. If your first test comes back positive and you deny drug use, you will be given a second test: a gas chromatography or a mass spectrometry. The procedure is no different than the first, an immunoassay. The test results take longer to get results and are more expensive but they rarely produce a false positive.
Did you know these facts regarding substances and the length of detection?
