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.

• Urine Testing
  
• Hair Follicle Testing
  
• Perspiration Testing (Sweat Ptch)
  
• Saliva Testing
  
• Blood Testing
  
• Fingernail Analysis
  
• Eye Drug Testing

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 tests. Other testing information can be found in our Drug Testing Books section.

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 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 testing system in place. Among other things, this required 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.

1. Cannabinoids (marijuana, hash)
2. Cocaine (cocaine, crack, benzoylecognine)
3. Amphetamines (amphetamines, methamphetamines, speed)
4. Opiates (heroin, opium, codeine, morphine)
5. Phencyclidine (PCP)

Expanded Tests

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 :

1. Barbituates (Phenobarbital, Secobarbitol, Butabital)
2. Hydrocodone (Lortab, Vicodin)
3. Methaqualone (Qualuudes)
4. Benzodiazepines (Valium, Librium, Serax, Rohypnol)
5. Methadone
6. Propoxyphene (Darvon compounds)
7. Ethanol (Alcohol)
   

Urine testing is the most common type of drug testing. 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:

Immunoassays

These tests 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 test. 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 testing mainly used by the military. Mistakes come from poor calibration. The manufacturer states that “a positive test result should be confirmed…”
FPI (Fluorescence Polarization Immunoassay) is manufactured by Abbott Laboratories. Fluorescent compounds mark the selective binding of antibodies to drugs and their metabolites. It is highly sensitive and highly specific.

Chromatography

TLC (Thin Layer Chromatography)
This procedure involves the addition of a solvent to the sample causing the drugs and their metabolites to travel up a porous strip leaving color spots behind. As each different substance travels a specific distance, the strip can then be compared with known standards. This test gives no quantitive information, it merely indicates the presence of drugs or their metabolites. Furthermore, it relies on the subjective judgment of a technician and requires considerable skill and training. False positives result from misinterpretations. It is not widely used.
GC/MS (Gas Chromatography/Mass Spectometry)
This is the most precise type of test for identifying and quantifying drugs or their metabolites in the urine. The GC/MS is routinely used as a confirmation test following a positive result on an Immunoassay. It involves a two step process, whereby Gas Chromatography separates the sample into its constituent parts and Mass Spectometry identifies the exact molecular structure of the compounds. The combination of Gas Chromatography and Mass Spectometry is considered to be the definitive method of establishing the presence of drugs or their metabolites in the urine. However, the equipment necessary to perform it is extremely expensive and this is reflected in the price for testing each sample. Occasionally problems do arise with poor calibration of the equipment. Mistakes also commonly happen if the machine is not thoroughly cleaned – samples can be contaminated by small traces from the previous urine sample. Temperature, pressure, and storage time of samples must be rigidly controlled.

Although urine is most commonly tested, occasionally laboratories use one of the following methods to detect the presence of drugs or their metabolites:

The technology behind the hair test was pioneered by Psychemedics Corporation in 1987. Psychemedics Corporation is the world's leading laboratory for the 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 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 testing.
When drug metabolites are circulated in the blood, they enter the scalp's blood vessels and are filtered through the hair. These metabolites remain in the hair and provide a permanent record of drug use. With a one-inch hair sample containing about 50 strands, labs can detect the use of drugs within the past three months.

A standard screen covers a period of approximately 90 days. 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. 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 sample from any part of the body.

Psychemedics Corporation (Amex: PMD) announced toda it has received 510(K) clearance from the Food and Drug Administration (FDA) for its test for the 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 test 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 testing is widely used in the casino industry. Companies such as Blockbuster Video and Subway perform hair follicle drug tests on all employees. Pschemedics markets their PDT-90 hair test 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.

Another hair follicle testing company: http://www.avitarinc.com/hairscreen.html

(Sweat Patch)

PharmaChem has produced a 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 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 patch is tamper proof and each one has a serial number.

The FDA has recently given Epitope, Inc approval to begin manufacturing saliva test. 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 test 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 test will be confined to detecting current intoxication only.

“Saliva testing has been touted as a "fitness for duty" test, as its window of detection begins as soon as a drug is ingested. Saliva tests 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 testing. Saliva 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, drugs will remain undetected in the first 4-8 hours.

• Marijuana 12-24 hrs
• Opiates 24-48 hrs
• Amphetamine 24-48 hrs
• Methamphetamine 24-48 hrs
• Cocaine 12-24 hrs

Saliva 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 testing for drugs of abuse may be successfully utilized in a variety of applications, including the following:

• Detection - employment, health exams, insurance
• Treatment - diagnosis, compliance, abstinence
• Forensics - reasonable suspicion testing, DUI, evidence investigation

LifePoint, Inc. – IMPACT System
The use of saliva as the specimen of choice adds significant advantages to the LifePoint IMPACT Test System when used for testing for drugs of abuse. Saliva offers the ability to obtain "current status" or "blood-equivalent" information for drugs of abuse, compared to urine testing results, which indicate prior drug use by an individual over 2-5 days. This is a very significant advantage since only a blood test done with sophisticated laboratory equipment can provide similar information. This advantage is extremely relevant in the initial market segments being targeted.

• Saliva is the only easily obtainable specimen in which the measured level of many analytes correlates with their corresponding levels in blood.
• Using saliva as a specimen provides for non-invasive and observable specimen collection compared to blood (invasive) and urine (not easily observable) as specimen types.
• Saliva is a "natural fit" as a specimen of choice for on-site testing.

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 testing because the originally collected volume of saliva is not known. Current on-site testing is often limited to a single test because multiple tests require large amounts of saliva.

There are two initial test 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 test 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 instrument allows you to obtain a near-simultaneous saliva sample to send to a laboratory for GC/MS confirmation.

The 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 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.

AVITAR INCORPORATED - ORALscreen
ORALscreenTM is the first rapid on-site oral fluid screening device for drugs of abuse testing. ORALscreen uses Avitar's proprietary polyurethane and oral fluid technology to detect up to four classes of drugs of abuse (opiates, marijuana, cocaine, and methamphetamine - including MDMA/Ecstasy). It takes only fifteen minutes to obtain accurate results.

Orasure Technologies, Inc. - Intercept
The Intercept™ oral fluid drug test was introduced in February as a collaborative effort of LabOne, STC Technologies, Inc., and Epitope, Inc. (NASDAQ: EPTO). All three companies play pivotal roles in the marketing of this new lab service. STC, the leader in oral fluid immunoassay technology, provides reagents as well as marketing support. Epitope produces the Intercept™ collection device and provides sales support for the criminal justice and public health markets. Laboratory testing, result report, workplace sales, and account management support are assumed by LabOne.
In partnership with several leading lab partners, OraSure Technologies markets Intercept®, the first laboratory-based oral fluid drug test. The Intercept® test serves the workplace and criminal justice drug testing markets.

Although expensive and intrusive, blood testing is the most accurate confirmation of drug use. Since blood 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 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 sample collection.

The eye test 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 scan test 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 manufactures claim a 97% accuracy rate. Problems with eye or nerve abnormalities raise questions about test accuracy.