Wednesday, November 27, 2013

How does drug testing work?

Most drug testing is broken down into four categories: urine, hair, saliva, and blood. The labs are not looking for actual drugs, but drug metabolites, which are the bi-product of drugs. Once a body takes in a substance, it processes that substance, and the end product looks much different than the beginning product.

Urine Drug Testing

Urine testing is the most common drug testing around. This is typically broken up into two types of tests: drug screen and drug test. Yes, these are two different things and most people are not aware of the differences.

First, let me explain the drug screen. This is a very simple dipstick test, where the technician simply dips a litmus strip directly into the urine sample, and will have a result within minutes. These are the same tests you can get in your local pharmacy or online. There are different types of these tests, but the most commonly used is a 5 panel test which tests for THC, Opiates, PCP, Amphetamines, and Cocaine. These tests are sometimes referred to EMIT, which stands for something long and hard to remember (Enzyme Multiplied Immunoassay Test), but most commonly it is referred to as a dipstick test, or instant screen.

Now this brings us to the drug test. This is scientifically referred to as a gc/ms test (Gas Chromatography/Mass Spectrometry) but is more easily referred to as a lab test. This is the most accurate type of urine testing. Basically what they do is send your urine through a machine, and the machine will spit out numbers that tell the levels of toxins if present. Most of the time, these two tests are used in conjunction with each other. What many labs will do is use the cheaper less accurate instant screen to initially screen your urine. This will give the lab a preliminary result as to if you are a drug user or not. If the instant test is negative, you pass. Way to go! If the test is positive, then they will do a confirmation lab test. This will give them a more precise result, eliminating any false positives that may have occurred on the instant test.

Certain people are subject to DOT drug tests, or Department of Transportation drug tests. These types of tests are regulated by the Department of Transportation and if the guidelines are not followed then the results are considered invalid. On these tests, an instant screen is always done first, and if the result is positive, the sample is sent for confirmation with a lab test. DOT will only test for five different substances: Marijuana, Opiates, Cocaine, Amphetamines, and PCP.

It is obvious to drug testing labs that people will try to manipulate their urine sample in order to pass their tests. For this reason, integrity tests are done on the urine sample in order to make sure this is a human urine sample that has not been tampered with. They will also check to make sure the urine is not diluted, meaning there is too much water in the urine. Once the urine sample has passed the integrity tests, it is free to be tested with an instant screen or lab test. Integrity tests are just a piece of litmus paper that they dip into the urine. This stick will test for several constituents of urine which include pH level, specific gravity, and creatinine. The lab will also check for several substances that could indicate the donor tried to adulterate the sample. Adulterating the sample means to put something in the urine that would cause it to test negative.

Hair Drug Testing

Hair testing is another type of test that labs will do to test for drugs. Toxins are circulated through your body via blood. When hair is formed, blood is deposited into the hair follicle. Your old blood actually becomes your hair. When you have toxins in your blood, the toxins are also deposited into the follicle and become trapped in your hair. The level of toxins is greatest near the scalp. Sunlight, shampoo, and chemicals used in hair dyes will help reduce the level of toxins in your hair. For this reason, they will clip the hair sample near the scalp, on the back (nape) of your neck.

The hair will then be sent to a laboratory where they dissolve the hair in organic chemicals. Once the hair is dissolved, the sample is tested just like a urine sample would be tested in a lab, with a gc/ms machine.

Saliva Drug Testing

Saliva testing is a very simple and fast way to test someone for drugs. This test is mostly done for pre-employment tests and is done onsite. Basically a stick with a sponge, sometimes called a swab, is put into your mouth. The tester is to run the swab over the tongue and against the cheek. It is then held in the mouth until the swab is fully concentrated with saliva. This saliva is put into a testing tube that contains a dropper on top. The tester will then drop saliva on a testing cartridge that contains litmus paper. The results will be ready in ten minutes.

Blood Drug Testing

Blood testing is really nothing to be concerned with when testing for drugs. Usually, if you are taking a blood test they will also perform a urine test. The blood is not being taken to test for drugs, but for diseases. You will usually see this when taking a test for life insurance. If for some reason they are doing a blood drug test, stay clean for two days. Drug toxins can only be detected in blood for 48 hours after consumption.

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