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.
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
- Cannabinoids (marijuana, hash)
- Cocaine (cocaine, crack, benzoylecognine)
- Amphetamines (amphetamines, methamphetamines, speed)
- Opiates (heroin, opium, codeine, morphine)
- Phencyclidine (PCP)
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 :
- Barbituates (Phenobarbital, Secobarbitol, Butabital)
- Hydrocodone (Lortab, Vicodin)
- Methaqualone (Qualuudes)
- Benzodiazepines (Valium, Librium, Serax, Rohypnol)
- Propoxyphene (Darvon compounds)
- 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:
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.
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
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
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
Another hair follicle testing company: http://www.avitarinc.com/hairscreen.html
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
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
- Detection - employment, health exams, insurance
- Treatment - diagnosis, compliance, abstinence
- Forensics - reasonable suspicion testing, DUI, evidence investigation
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
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
Inc. - 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
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.