Drug Testing Info: Types of Drug Testing
To understand the principles behind drug testing technology, some knowledge is required about the way in which the body deals with chemical compounds such as drugs. Irrespective of the method of intake, all drugs, pharmaceutical and otherwise, undergo a series of bio-chemical reactions in the body. These reactions release the active compound and then gradually degrade the drug into slightly different structures. These structures, also called metabolites, are then excreted from the body in a variety of ways.
What do labs test for?
The first thing to know about drug testing is what the standard test looks for. What is being tested for varies greatly based on testing company, expense, expectations, federal requirements etc. Following is a description of what to expect from the standard drug testing.
Marijuana, cocaine (including crack), opiates (including heroin), methamphetamine, phencyclidine (PCP or angel dust), and ecstasy (MDMA). These drugs were identified as "illegal drugs" in the Presidents Executive Order 12564 and are the five drugs mandated for drug testing by the federal government
The NIDA 5 Federal government guidelines (by NIDA-The National Institute on Drug Abuse and SAMHSA-The Substance Abuse and Mental Health Services Administration) require that companies which use commercial class drivers licenses for employees must have a drug testing system in place. Among other things, this required drug testing program must test for 5 specific categories of drugs (sometimes referred to as the "NIDA 5"). Because of this federal requirement, most drug testing companies offer a basic drug test which checks for drugs in these 5 common categories. Click on the substance name for a description of the laboratory method for detecting the substance.
Expanded Drug Testing
Most drug testing companies also offer an expanded test which includes a few additional drugs in the testing process. Most do not add all of these in their expanded test, but choose a different combination of 3 or 4 to add :
Urine Drug Testing
Urine drug testing is the most common type. Urine is the specimen of choice since it contains the most metabolites of a drug taken. Urine is the main excretory route for drugs and their metabolites. The following is a summary of the analytical methods used by laboratories to detect the presence of drugs or their metabolites in the urine:
These drug testing procedures are most commonly used to screen samples. In the event that drugs or their metabolites are detected, then the sample is normally tested again using an even more sensitive test such as Gas Chromatography and Mass Spectometry. Immunoassays work on the principle of antigen-antibody interaction. Antibodies are chosen which will bind selectively to drugs or their metabolites. The binding is then detected using either enzymes, radioisotopes or fluorescent compounds.
EMIT (Enzyme Multiplied Immunoassay Technique) is manufactured by Syva Laboratories. It uses an enzyme as the detection mechanism. It is the cheapest, simplest to perform and the most widely used of the immunoassays. The EMIT is commonly used by employers as an initial drug testing step. The EMIT is the most commonly used test for pre-employment screenings despite having a 4-34% "false positive" rate.
RIA (Radio Immunoassay) is manufactured
by Roche Diagnostics. It is similar to EMIT but uses a radioactive isotope
such as iodine instead of an enzyme. However, because it involves using
radioactive substances, it is less popular than EMIT. This is a highly
sensitive form of drug testing mainly used by the military. Mistakes come from
poor calibration. The manufacturer states that “a positive test result
should be confirmed…”
TLC (Thin Layer Chromatography)
Although urine is most commonly tested, occasionally laboratories use one of the following methods to detect the presence of drugs or their metabolites:
Hair Follicle Drug Testing
The technology behind the hair drug
pioneered by Psychemedics Corporation in 1987. Psychemedics Corporation is
the world's leading laboratory for the drug testing of hair for the presence of
drugs. Its client list includes over 2,200 corporations (over 10% of the
Fortune 500), which use hair drug testing as part of their drug-free workplace
programs. In addition, five of the country's largest police departments as
well as schools and Federal Reserve Banks rely on Psychemedics' hair
A standard screen covers a period of approximately 90 days. The hair drug testing sample is cut as close to the scalp as possible and the most recent 3.9 centimeters (approximately 1 1/2 inches) are tested. The hair sample is cut as close to the scalp as possible and the most recent 3.9 centimeters (approximately 1 1/2 inches) are tested. Assuming the sample is taken from the head, the amount of hair needed is a snip about the thickness of a shoelace tip.
Hair can be collected from several locations on the head and combined to obtain the required amount of hair. If necessary, body hair can be used as an alternative to head hair. If you have very short hair, labs can take a drug testing sample from any part of the body.
Psychemedics Corporation (Amex: PMD) announced today it has received 510(K) clearance from the Food and Drug Administration (FDA) for its drug testing detection of marijuana use through human hair analysis. Psychemedics has now received FDA clearance for the five drug panel routinely used in drug testing.
Psychemedics' marijuana drug testing system employs radioimmunoassay for the qualitative screening and mass spectrometry for quantification of carboxy -- THC in hair for the purpose of identifying marijuana use.
The hair is clipped and then dissolved in a series of solvents. Psychemedics' patented technology that detects drugs in hair using radioimmunoassay. RIAH® (Radioimmunoassay of Hair) measures the drug molecules permanently entrapped in hair which were incorporated following ingestion. The laboratory then analyzes the liquified sample using Gas Chromatography and Mass Spectometry. This makes it a highly sensitive test, yet the considerable cost and prolonged process means that it isn't often used. It also usually requires a confirmation test using urine.
People with dark hair are 10-50 times more likely to test positive for drug use. Hair drug testing is widely used in the casino industry. Companies such as Blockbuster Video and Subway perform hair follicle drug testing on all employees. Pschemedics markets their PDT-90 hair drug testing collection kit to parents to be a deterrent to drug use and to tell whether a child has used drugs in the previous several months. The PDT-90 is available in some pharmacies and drugstores.
PharmaChem has produced a drug testing patch which is worn on the skin for a period of time. The patch contains a mechanism which is able to detect the presence of drugs or their metabolites as they are excreted in the individual's perspiration. The drug testing patch is used mainly to monitor individuals who are on parole or probation. The use of the sweat patch to detect drug use was recently approved by the FDA. The patch is used mainly to monitor people on parole or probation. The drug testing patch is tamper proof and each one has a serial number.
Saliva Drug Testing
The FDA has recently given Epitope, Inc approval to begin manufacturing saliva drug testing. In a study using RIA (Radioimmunoassay) test, cannabinoids were detected in saliva 4 to 10 hours after subjects smoked a single marijuana joint. Epitope has recently developed a test which detects drugs or their metabolites in saliva. However, this sort of drug testing is limited to detecting very recent drug use. In one study, saliva testing was only able to detect cannabinoids 4-10 hours after the subjects had been smoking. It is likely that this drug testing will be confined to detecting current intoxication only.
“Saliva drug testing has been touted as a "fitness for duty" test, as its window of detection begins as soon as a drug is ingested. Saliva drug testing will reveal only current or very recent (within the past twelve hours) marijuana use, but will detect use of cocaine, opiates, methamphetamine and Ecstasy over the past two to three days (urine will detect these drugs for three or four days after use). Saliva is typically experienced as cleaner and less intrusive than urine, and there are currently no known methods for defeating saliva drug testing. Saliva drug testing testing is useful for pre-employment, random, post-accident and for-cause testing. Both lab-based and on-site systems are available; the on-site system offers results ten minutes after taking the saliva sample. Saliva tests compare favorably in price to urine testing. "
In oral fluid, drugs will be detected within minutes after use.
In urine drug testing, drugs will remain undetected in the first 4-8 hours.
Saliva drug testing for drugs of abuse can provide both qualitative and quantitative information on the drug status of an individual undergoing testing. Self-administration by the oral, intranasal, and smoking routes may result in contamination of the oral cavity. Generally, the level of drug detected in the oral cavity is related to the relative acidity of the saliva and there are established chemical relationships that can be used to estimate the blood level once the saliva level and its relative acidity are known. Since there is a high correlation of saliva drug concentrations with plasma, the application of saliva drug testing for drugs of abuse may be successfully utilized in a variety of applications, including the following:
Inc. – IMPACT System
Previous attempts to use saliva as a test specimen have been limited to the use of absorption as a collection methodology. Absorption has significant limitations, including a slow collection time and potential loss of an analyte due to absorption in the collection pad. Additionally, collection for transport to lab does not allow for quantitative drug testing because the originally collected volume of saliva is not known. Current on-site drug testing is often limited to a single test because multiple tests require large amounts of saliva.
There are two initial drug testing panels to choose from. The first panel performs the National Institute on Drug Abuse (NIDA) 5 drugs (marijuana, cocaine, PCP, amphetamines/methamphetamines, and opiates). The second panel performs the NIDA-5 drugs plus alcohol.
We will rapidly expand the drug testing menu. Future drug tests include Benzodiazepines, Barbiturates, Ecstasy, and TCA (tri-cyclic antidepressants). These will be available in a wide variety of panel formats to meet market requirements.
The drug testing instrument allows you to obtain a near-simultaneous saliva sample to send to a laboratory for GC/MS confirmation.
The drug testing system has all the necessary attributes to become "evidentiary" (i.e., instrument read, outstanding quality of result, etc.), and meets the Frye and Daubert standards for court admissibility. However, since the system is just coming to market, it has not yet been tested in a court case.
Saliva collection AND drug testing with the IMPACT Test System take less than 5 minutes.
LifePoint will be submitting our alcohol test for DOT approval as an evidentiary test. The DOT has not yet approved any on-site or saliva products for drug testing. However, SAMHSA guidelines are being reviewed to include saliva and on-site tests as acceptable by DOT.
LifePoint has initially targeted the law enforcement, industrial workplace and emergency room markets.
Technologies, Inc. - Intercept
Blood Drug Testing
Although expensive and intrusive, blood drug testing is the most accurate confirmation of drug use. Since blood drug testing accurately detects the presence of the drug or its metabolites at the time of testing, the results from this type of test are the best indication of current intoxication. Blood drug testing for the use of drugs is primarily used in accident investigations and for health insurance or life insurance exams. Marijuana can be detected up to six hours after consumption by testing blood; after that, the metabolite concentration falls rapidly, and cannabinoids are not detectable in the blood after 22 hours.
Fingernails, like hair, are made of the protein keratin. Results of a fingernail sample will represent drug use that is approximately 4-5 months from the time of ingestion. Fingernails can be clipped, or, if length does not allow, can be shaved in a safe and pain-free drug testing sample collection.
Eye Drug Testing
The eye drug testing is made by PMI Incorporation, based in Maryland. The test consists of a pair of goggles hooked up to a computer, and it uses light to measure pupil size and reflex to light. The readings are compared against a previously established baseline, and if the pupil is dilated or reacts more slowly then the test shows positive. The eye scan can only determine if the person is currently impaired and can not determine if impairment is caused by drugs, alcohol, and lack of sleep or other causes. Generally, a person that tests positive on an eye drug testing scan will be subjected to a subsequent urinalysis to determine what toxin is causing the impairment. Two other similar tests, the EM/2 and FIT tests measure the rapid eye movement of the pupil. The drug testing manufactures claim a 97% accuracy rate. Problems with eye or nerve abnormalities raise questions about test accuracy.
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