Absorbance

The amount of light that does not pass through a solution. The Beers-Lambert Law is a mathematical principle used to demonstrate that the amount of light absorbed by a particular substance in solution is directly proportional to the concentration of that substance.

Absorption

The passage of the drug from the site of administration into circulation.

Accuracy

The agreement of a measured value with the absolute, defined amount of whatever is to be measured. A drug test is accurate if it agrees with the accepted or gold standard.

Affinity

A measure of the strength of binding between antibody and antigen; expressed in terms of "high" or "low" affinity.

Agglutination

A reaction during which an antibody causes particulate antigens in suspension to clump together (See precipitation below).

Amino Acids

Basic chemical units of proteins.

Amphetamines

"Amphetamines" refers to a class of materials with a molecular structure resembling that of amphetamine. The term "amphetamines" includes amphetamine itself, methamphetamine, certain "designer drugs", certain over-the-counter (OTC) cold medicines, and others. (Most common are d-amphetamine, d-methamphetamine, and dl-amphetamine.)

Amphetamines stimulate the central nervous system to produce wakefulness, alertness, increased energy, reduced hunger, and an overall feeling of well-being. Amphetamines can be taken orally, intravenously, by smoking, or by snorting. Amphetamines appear in the urine within 3 hours after any type of administration, and usually can be detected in urine for as long as 24 to 48 hours after the last dose. Typical therapeutic doses of amphetamine and methamphetamine are usually between 5 to 10 mg, though tolerant methamphetamine abusers have been reported to consume up to 2 g daily.

Amyl nitrate or Butyl nitrate (Poppers, whippets, RUSH, Locker room)

Amyl nitrate has been used therapeutically to produce coronary vasodilatation in angina patients and as an antidote to cyanide poisoning. Amyl nitrate is held in a fragile glass capsule secured in a cardboard tube by two porous wands. The tube is bent slightly to shatter the capsule (this makes a popping noise and accounts for the street name "poppers"). The resulting vapor is inhaled by the user-this produces methemoglobin and is the reason for the subsequent physical "rush" felt. Effects include headache, flushing of the face, decreased blood pressure, increased pulse, dizziness, and relaxation of involuntary muscles. The effects only last a few minutes. Poppers are commonly used to heighten sexual arousal.

Alkyl nitrates (poppers)

The nitrate-containing products found on the street are packaged specifically for the illicit market. They usually contain butyl or isobutyl nitrate and are often very impure. The smell is distinctive-sweet and sickly. A side effect of the use of these compounds can be severe headache.

Antibody

A soluble protein produced by a B lymphocyte in response to a foreign invader.

Antigen

A foreign substance; a substance that is capable of stimulating an immune response and can combine with an antibody (See Immunogen below).

Antigenicity

A feature of an antigen, such as its size, which defines its ability to be recognized by an antibody.

Antigenic determinant

An antigenic site; a single site on an antigen to which a specific antibody binds. This is also called an epitope.

Antiserum

Serum that contains antibodies for a specific antigen.

Assay

Analysis to determine the presence, absence, or quantity of one or more components, also known as a test.

Ayahuasca (yaje, vine of the souls, vine of the dead)

A hallucinogenic drink brewed from one or more dimethyltryptamine (DMT) plants. It is used in many religious rituals in South America. The drink is a Schedule I drug, though the plants are not scheduled. It is generally taken with an MAO inhibitor, such as harmine or harmoline, to activate the DMT, and this may cause life threatening risks. The leaves can also be dried and smoked.

Benzodiazepines

Benzodiazepines are sedative–hypnotic central nervous system (CNS) depressants. They work with the g-aminobutyric acid (GABA) receptors of the CNS. GABA is a neurotransmitter stored in the nerve cells and released by the brain to calm the body. Common benzodiazepines include chlordiazepoxide (Librium), diazepam (Valium) and oxazepam (Serax). The different benzodiazepines are absorbed at different rates and the timing of their psychoactive effects varies with the absorption rate. Benzodiazepines are usually taken orally and are metabolized in the liver. Some metabolites are pharmacologically active. Benzodiazepines potentiate the effect of other CNS depressants, such as ethyl alcohol.

Flunitrazepam (Rophies, Roophies)

Flunitrazepam is a benzodiazepine that has never been approved for use in the U.S. It is the most commonly used "date rape" drug.

Bufotenine (Toad Licking)

Bufotenine was the subject of some media attention several years ago, and is thought to be abused very little, if at all. The Colorado River Toad secretes a venom that contains bufotenine. Heat (smoking) breaks down the toxic substances, and 5-MeO-DMT, a hallucinogen, remains. The milky venom is squeezed from the toad’s parotid glands. The "trip"is 100 times more potent than LSD or mushrooms and occurs instantly, lasting 5 to 15 minutes.

Bind

To combine with, lock together.

Binding

The chemical process of combining molecules by means of reactive groups.

Buffer

A chemical compound added to a solution to maintain a specific pH.

Buprenorphine

Buprenorphine is a methadone replacement drug that has just been approved for use to treat heroin addiction in the US It has been in use in other countries for several years.

Calibrators

Samples that contain a known amount of drug and are used as a reference or standard

Cannabinoids, Cannabis

Cannabis includes all psychoactive drugs derived from the dried leaves and flowering tops of the female plant Cannabis sativa L. The agents that produce the hallucinogenic and other biological effects of marijuana are called cannabinoids, of which there are about 60 compounds.

Cannabis has been used for centuries in some societies, and was once used as a mild tranquilizer. Today, it is estimated that over 25 million Americans are currently marijuana users, including 16% of high school students.

The cannabinoid ?9-tetrahydrocannabinol (?9-THC) is the principal psychoactive ingredient in marijuana and hashish. The compound ?9-THC is quickly and effectively absorbed by inhalation or through the gastrointestinal tract, and is almost completely metabolized by liver enzymes. The concentration of THC in marijuana can range from 1% to 7%; sinsemilla is a specialized strain with a high THC content. Hashish usually contains higher levels, and hash oil may contain up to 50% or 60% THC.

Hashish

Hashish, small lumps of cannabis resin, is usually brown in color, sometimes with a green tinge. Hashish is often used in addition to marijuana leaves.

Nabilone

Nabilone is a synthetic cannabinoid used as an anti-emetic and anxiolytic. It is used for the control of nausea and vomiting associated with cancer chemotherapy in patients who have failed to respond to conventional anti-emetics. The usual dose for adults is 1-2 mg twice per day. Although it is only available in hospitals and is unlikely to be abused, a user will give a positive urine immunoassay test for cannabis.

Carrier

An immunogenic molecule, or part of a molecule, that is recognized in an antibody response.

Catalysis

The acceleration of a chemical reaction by a substance (a catalyst or enzyme) that is not changed in the process.

Change in Absorbance (?A)

The difference between the initial reading and the final reading of the amount of light absorbed by a sample.

"Chasing the Dragon"

Street name given to smoking heroin. Heroin powder is placed on aluminum foil and heated underneath with a flame. Vapors are inhaled through a tube, often made from aluminum foil.

Class

A group, set, or kind sharing common attributes.

Clone

A group of identical cells, all of which are produced from a single cell.

Cocaine

Cocaine is a highly addictive stimulant of the central nervous system derived from the cocoa plant. Cocaine is commonly inhaled but may be self-administered in a number of different forms. Cocaine base can be smoked in a form known as "crack". It can also be injected as a cocktail with heroine, known as a "speedball".

Crack

Crack consists of small fragments or "rocks" of freebase cocaine, about the size of a raisin. They are cream to white, beige or yellow in color and of similar appearance to washing soda or candle wax. Crack is commonly found wrapped in aluminum foil. Crack is free-base cocaine, but is not the same as "free basing," which is not as popular any more.

Free basing

Free basing is the purification of street cocaine by mixing it into a liquid containing baking soda or ammonia. Ether is then added and the free-base cocaine is extracted and the ether is then evaporated. The free base is then smoked. This can be risky, as any remaining ether could ignite.

Coefficient of variation

A percent that represents the percentage of deviations from the mean; abbreviated %CV

Co-enzyme

Also called a "cofactor," a co-enzyme is an additional enzyme required in some enzymatic reactions.

Comparative Analysis

A way of determining the accuracy of an assay method in comparison to known, "true" values.

Constant error

A consistent bias in a comparative analysis where the value returned by the assay being tested is the sum of the true value and a constant.

Control

A sample that contains either a known amount of drug or no drug at all and is used to check the system (instruments, reagents, and operator).

Controls

Reagents with a known amount of substance to be tested; used to check the accuracy of an assay.

Correlation

The degree of interdependence between two variables.

Correlation Coefficient

The number that describes the degree of interdependence between two variables with 1.00 as being "ideal".

Cross Reactivity

A reaction of an antibody with an antigen other than the one that induced its formation (the cowpox/smallpox connection), or with more than one antigen.

DAT

Drugs of abuse testing.

Delay Time

Time from the start of the reaction to the initial absorbance reading.

Designer drugs

Designer drugs are illegally manufactured chemicals whose molecular structures have been altered slightly from a parent compound to enhance specific effects. Several forms of designer drugs are in the amphetamine class. Examples include DMT, DMA, DOM, MDA and MDMA (ecstasy). Designer drugs are commonly used at all-night dance parties called "raves." Other variations are: 2-C-T-7, 5-MeO-AMT, 5-MeO-DIPT (FOXY), 5-MeO-DMT DOB, and AMT, and have various street names.

Dextromethorphan (DXM, Triple C)

Dextromethorphan is contained in Coricidin Cold and Cough Medicine, which is sold as an over-the-counter cold medication. An extreme dosage – ie half an 8 oz bottle of cough syrup, creates hallucinogenic effects and must be consumed quickly to avoid vomiting. It is a dissociative drug and abuse among youth is rising.

Endpoint testing

The measurement of a product of a chemical reaction taken before and after the reaction.

Enzyme

A protein that speeds up or enhances (catalyzes) a chemical reaction.

Enzyme-labeling

Binding an enzyme to an antigen (drug).

Epitope

Antigenic determinant, or site on an antigen to which an antibody binds.

Express

Expel by pressure.

Final Absorbance Reading

The last absorbance reading.

Fluorescence

The ability of some chemicals to emit light.

Fragmentation Spectrum

The pattern created by a particular molecule after it has been shattered by a mass spectrophotomer.

Gammahydroxybutyrate, (GHB, GBH)

GHB has been used legitimately as an anesthetic adjunct and, experimentally, to treat posthypoxic cerebral edema and ethanol withdrawal in some countries outside the US There is no license for the product in the UK and therefore no therapeutic indications, although it is used in Germany and Italy. GHB has been marketed illicitly to body builders and has also been promoted illicitly for weight control and as a sleep aid. It is also known as one of the "date rape" drugs.

Globulin

A class of simple proteins which is present in serum; antibodies are known as immunoglobulins.

Gold Standard

The test of standard against which other tests and measures are evaluated for accuracy.

Hapten

A small non-antigenic molecule to which a large carrier protein is added, so that the hapten/protein carrier complex can be recognized by the immune system. Drugs of abuse are haptens.

Heroin (diamorphine injection)

Heroin is a potent, widely abused opiate that produces a profound addiction. It consists of two morphine molecules linked together chemically. Heroin is a drug of abuse that may be snorted, smoked, or dissolved and injected subcutaneously or intravenously.

Heterogeneous

In a heterogeneous assay, the unbound label must be separated from the test solution because the label activity is not affected by antibody binding. This type of immunoassay requires a separation step.

Homogeneous

In a homogeneous assay, the reactants and the byproducts can remain in the same solution when the results are determined because the activity of the label is changed when bound by an antibody. This type of immunoassay does not require a separation step.

Host

An animal or plant that harbors another organism

Hybridoma

Transformed cell line grown in vivo (in the live animal) or in vitro (in a test tube or culture) that is a hybrid of 2 parent cell lines and contains genetic material from both

Immunity

The condition of being able to resist a particular disease.

Immunize

To induce an immune response, ie to cause the body’s immune system to react to something.

Immunoassay

A test that utilizes antibodies.

Immunochemical

A term used to describe a technique by which chemical reactions are used to detect antigens.

Immunogen

A foreign substance; a substance capable of stimulating an immune response (See Antigen above.)

Immunogenicity

Ability to cause the body to mount an immune response.

Immunoglobulin

An antibody is known as an immunoglobulin because it is a soluble protein which takes part in the immune response.

Initial Absorbance Reading

The first absorbance reading.

Jimsonweed (Jamestown weed, Angel’s trumpet, Devil’s trumpet, loco weed)

Datura stramonium is a member of nightshade family (including belladonna) and can be smoked, eaten, or brewed. It contains atropine and scopolamine, and grows wild throughout the US Effects include delirium, hallucinations, blurred vision, confusion, agitation and combative behavior. Ingestion has led to seizures, coma, and death. Onset occurs within 1 hour and can last up to 24 hours. There is no antidote for Jimsonweed poisoning.

Kava-Kava

Piper methysticum is member of pepper family. The root is usually brewed and drank as a tea. Kava-kava also is found in many supplements. It has sedative and anti-anxiety properties, and can cause severe liver damage.

Ketamine HCl

Ketamine is a dissociative anesthetic used in human and veterinary medicine. It produces marked analgesia, which may persist into the recovery period. It may be administered by intravenous or intramuscular injection. It has been seen on the streets as tablets often containing other drugs such as ephedrine and sometimes marked in the same way as tablets containing MDMA (Ecstasy). It is known as "wobbly E" due to the loss of balance and coordination it causes.

Khat

Khat contains two known pharmacologically active substances, cathinone and cathine (norpseudoephedrine). They are related to ephedrine and phenylpropanolamine. Cathinone is the main active ingredient. Its concentration in the fresh leaves ranges from 0.3 to 2.1% depending on the origin and variety of the plant. Cathine concentrations range from 0.7 to 2.7%. The active ingredients start to deteriorate two days after the plant has been harvested, so it must be consumed fresh.

Cathinone and cathine are controlled under the United Nations Convention on Psychotropic Substances. They are class C drugs (the category with the lowest penalties). Cathinone may not be lawfully possessed, supplied, etc, except under a license for research or other special purposes.

Kinetic Testing

The measurement of a product of a chemical reaction as the reaction takes place.

Label

A chemical bound to the antigen in an immunoassay that allows the detection and measurement of the antigen (enzyme, radioisotope, or fluorescent molecule, for example).

Legal Herbal Highs

There is a variety of herbs, and drugs derived from them, with psychoactive properties, which may be misused in ways similar to illegal drugs. They are not controlled by law, for various reasons. Examples of such herbs are:

Betel Nut – A member of the palm family, Betel Nut contains a mild stimulant. In Asian countries, the seed of the palm tree is wrapped in the leaf of the betel pepper (Piper chavica betel), sprinkled with lime, catechu gum from the Malayan acacia tree (Acacia catechu) and various spices and then sucked and chewed.

Calamus – Sweet flag root (Acorus calamus) belongs to the Arum family. The roots are collected in spring or autumn, dried then chewed or brewed into a tea. The active principle is asarone, which is a stimulant and hallucinogen, but has also been reported to have sedative effects. The herb, Acorus, is used as a carminative but the oil may be carcinogenic.

Catnip – The leaves of the Nepeta cataria can be smoked to produce a mild euphoria.

Hops – Humulus lupulus is a member of the Cannabinacea family and is the ingredient in British beer that is responsible for its characteristic bitter flavor. Dried hops can be smoked to produce a mildly sedating, cannabis-like high.

Thorn Apple – The leaves of Datura inoxia, a member of the potato family (Solanaceae), may be smoked to produce a mild intoxication.

Leukocytes

White blood cells, one component of the blood (along with red blood cells, plasma, etc).

LSD

Lysergic acid diethylamide (LSD, acid) is one of the most potent hallucinogenic agents known. LSD produces vivid hallucinations in all of the sensory modalities. These symptoms generally last 6 to 12 hours and gradually decline in intensity. Users experiencing a "bad trip" may exhibit hysterical behavior, hyperactivity, life-threatening hyperthermia, restlessness, anxiety, numbness, vomiting, collapse, coma, and fever, among other reactions. Delayed psychotic reactions can occur weeks after ingestion.

Macromolecule

A large molecule, usually a protein or a combination of proteins and fats (lipoproteins) or proteins and sugars (glycoproteins).

Magic mushrooms

Magic mushrooms, also known as "Shrooms," have hallucinogenic properties similar to LSD. The psychoactive chemical is psilicibin. Hallucinogenic mushrooms have been used for centuries, especially in Mexico and Central America. The mushrooms can be consumed raw, dried, cooked or dried and crushed into tablets. The use of mushrooms is most common among teenagers, but is still not as popular as LSD.

Malignant

Growing out of control, living indefinitely; description of a tumor which can invade adjacent tissues and metastasize (travel to different parts of the body).

Mean

The average of values.

Measure Time

Time from initial reading to final reading.

Mediate

Facilitate by indirect means, ie to affect another action.

Methadone

Methadone is a synthetic narcotic/analgesic drug that is administered orally or intravenously. Medically assisted withdrawal from opioids is usually accomplished using methadone. Methadone is frequently used in maintenance programs as a substitute for heroin or other abused opioids while allowing the subject to successfully participate in drug rehabilitation. Patients are able to function well on methadone and perform complex tasks competently. Methadone can be abused, and methadone maintenance subjects often sell the methadone on the street.

Methamphetamine (ice)

Methamphetamine belongs to the class of amphetamines, yet has a half-life of 12 hours or more compared to amphetamine’s half-life of only 7 hours or more and is thus widely preferred as a drug of abuse. A highly purified form of methamphetamine called "ice" because of its crystalline structure, is usually prepared as the freebase for smoking. Pharmaceutical use of methamphetamine is limited to attention deficit disorder and obesity, and is available for such uses as the pure d-isomer. The l-isomer is available as a nasal decongestant in Vicks inhalers and has only very mild stimulant properties.

Mobile phase

In chromatography, an organic solvent or inert gas that carries the sample through the stationary phase.

Molecular weight

The combined weight of the atoms that make up a molecule.

Myeloma

A tumor of plasma cells. (See plasmacytoma, below).

Nanometer (nm)

One billionth of a meter and the unit used to measure the wavelength of light

Nexus – 2CB

Nexus – 2CB has been sold as Ecstasy, but is not true MDMA. It is a phenethyalmine which causes hallucinations. It is a Schedule I drug, and seizures have increased in recent years.

Nitrous Oxide, N20

Nitrous oxide is an inhalant also known as "laughing gas." Nitrous oxide is a weak anesthetic that does not produce unconsciousness. Nitrous oxide can be inhaled from empty whipped cream dispensers, which use capsules of the gas.

Nonself

Not belonging to self, foreign to self, having different genetic characteristics (See self below).

Opiates

Opiates are a class of compounds that includes morphine, codeine and heroin. Morphine and codeine are naturally occurring alkaloids that are found in opium, a substance exuded from the unripe seedpod of the opium poppy, Papaver Somniferum.

Morphine is a potent analgesic. Codeine is used in analgesic preparations and as a cough suppressant. Heroin is an even more potent analgesic than morphine. Opiates are absorbed rapidly.

Dihydrocodeine (Synalgos®-DC) is a semi-synthetic opiate structurally similar to codeine. Dihydrocodeine is used to treat mild pain, and is taken orally.

Hydrocodone (Hycodan®, Vicodin®) is a semi-synthetic opiate structurally similar to codeine. Hydrocodone is used to treat moderate or severe pain and severe coughs. Hydrocodone is more potent than codeine, and is taken orally as tablets, capsules or syrups.

Hydromorphone (Dilaudid®) is a semi-synthetic opiate structurally similar to morphine, but is much more potent than morphine. Hydromorphone is used to treat moderate or severe pain, and can be taken orally, or by injection. When taken orally, it is not as effective as when injected. It is often sought after by narcotic addicts, and is usually obtained by the abuser fraudulently. The tablets can be dissolved and injected as a heroin substitute.

Oxycodone (Percodan®, Percoset®) is a semi-synthetic opiate structurally similar to codeine made from thebaine, with about the same potency of morphine. It has a high potential for addiction. Oxycodone is used to treat moderate pain, and is taken orally.

Oxymorphone (Numorphan®) is a semi-synthetic opiate structurally similar to hydromorphone. Oxymorphone is used to treat moderate or severe pain, is given rectally or by injection, and is much more potent than morphine.

Oxycodone (Oxycontin®) is a recently marketed slow-release formulation. It is a semi-synthetic narcotic analgesic used to treat moderate to severe pain. In recent years, Oxycontin has received much media attention due to a rash of overdoses and deaths.

Particulate

A term used to describe particles which are suspended in or mixed with, but not dissolved in a liquid.

pH

The measure of the acidity of alkalinity of a solution.

Phagocytosis

The engulfing or ingestion of foreign material by a cell.

Phencyclidine (PCP, Angel Dust, Rocket Fuel)

Phencyclidine is a synthetic drug that was originally developed for its anesthetic properties but is now a drug of abuse used solely for its potent hallucinogenic effects. It may be self-administered in a variety of ways, including ingestion, inhalation, and intravenous injection. PCP is absorbed well and quickly and concentrates in the brain and fatty tissues. Excretion patterns vary widely, ranging from several hours to a couple of weeks. PCP is excreted in the urine unchanged, as conjugated metabolites, and primarily as unidentified compounds.

Photometer

An instrument used to measure the intensity of light transmitted by a solution.

Plasma

One component of blood; liquid in which blood cells are suspended.

Plasmacytoma

Tumor (-oma) of plasma cells (plasmacytes), ie an abnormal growth of plasma cells; this tumor is also called myeloma. (Plasma cells are related to B lymphocytes).

Polypeptides

Chains of amino acids which make up portions of proteins.

Poppy seeds

Poppy seeds do contain enough morphine and codeine to yield a positive urine immunoassay drug test for opiates. There is great variability in the amount of consumed poppy seeds required to yield a positive immunoassay result. Thebaine is the key compound associated with poppy seed ingestion, and thebaine analysis may be used to determine if poppy seeds could be the cause for a positive drug screen.

A reaction during which an antibody causes solid antigen particles in solution to clump together (See agglutination above).

Precipitation-Inhibition

A reaction which prevents precipitation from occurring.

Precision

The ability to get the same answer (right or wrong) over and over again.

Product

The substance made by the action of an enzyme on its substrate.

Proportional error

A consistent bias in a comparative analysis where the value returned by the assay being tested is the product of the true value and a constant.

Protein

Complex nitrogen compounds, composed of amino acids, which occur naturally in plants and animals.

Qualitative

A type of test that determines the presence or absence of a substance in a sample.

Quantitative

A type of test used to determine the concentration or amount of substance in a sample.

Radiant energy

Energy that travels in waves. In drug testing, the light of specific wavelengths is used to detect the presence of specific channels.

Read time

The time between the initial and the final readings of absorbance (measure time).

Reagents

The chemicals used to initiate a chemical reaction.

Receptor

A site present on a specific cell that is able to bind with an antibody.

Recovery study

A study assaying samples containing a known amount of a substance by testing "spiked" samples.

Reduced

Chemically changed; in an Emit reaction, NAD is reduced to NADH.

Regulate

To control or direct.

Retention time

In chromatography, the time it takes a particular molecule to move through the column or solid phase.

Salvia divinorum (Ska Maria Pastora, Diviner’s Sage, Salvia D)

Salvia divinorum is a plant that contains the hallucinogen salvinorin A. The plant or liquid extract can be purchased and use has been increasing as it is not Federally regulated. A perennial in the mint family, resembling sage, it is similar to cannabis and absinthe (wormwood) and can be smoked, chewed, brewed or liquified and vaporized/inhaled. The effects last for about an hour and include "out of body" experiences, feelings of merging with inanimate objects’, and synesthesia – ie hearing colors, smelling sounds. Mazatec Indians use it in healing ceremonies to induce visions.

Sample

The urine, plasma, or serum to be tested.

Scattergram

A graph on which results represented by points are "scattered"; in drug testing, the values resulting from the assay being tested are plotted against reference values.

Self

Belonging to oneself, identical, having the same genetic characteristics (See nonself above).

Sensitivity

The minimum amount of substance an assay can detect accurately and reliably. (In layman’s terms, the lowest amount of substance the test is able to detect.

Serum

Liquid which remains after blood cells clot.

Slope

The "pitch" of the best-fit line (eg drawn on a scattergram) that comes closest to including all the points on the graph.

Soluble

A term used to describe a substance which is dissolved in a liquid.

Solution

A liquid containing a dissolved substance.

Specificity

Restricted in application or effect to a particular structure or function; in immunology, pertaining to the special affinity of an antigen for the corresponding antibody.

Standard curve

A straight line established by running a series of assays using standard calibrators spiked with known amounts of the compound being studied over a range; results of unknown samples assayed are compared to the standard curve.

Standard Deviation

The average deviation or difference from the mean; abbreviated SD or s.

Standard Error of the Estimate

The number of scatter points around the slope; abbreviated SEE.

Stationary phase

In chromatography, the material (silica gel, ion-exchange resin, etc) through which the mobile phase migrates.

Steady state

The goal of drug therapy; equilibrium between the amount of drug administered and the amount of drug absorbed by the body.

Substrate

The substance an enzyme acts on.

Suspension

The state of a substance when its particles are mixed with, or suspended in, but not dissolved in, a liquid.

System

The elements necessary to carry out a drug test, including the instrument, the chemistry (reagents), and the operator.

Cell to which something is directed.

Target drug

The drug to which something is directed.

TDM

Therapeutic Drug Monitoring: The monitoring of serum drug concentrations in a patient so that a physician can administer the correct therapeutic dose; an aid to clinical judgment to assure efficacy in acute and chronic therapy, avoid toxicity, and determine or increase compliance.

Therapeutic range

The range of drug concentrations associated with a high degree of efficacy and low risk of dose-related toxicity in the majority of patients.

Vaccination

The introduction of vaccine, made from a weakened version of an organism, into a healthy person to produce immunity to the naturally occurring disease.

Vaccine

A weakened or dead version of an antigen, usually a microorganism, originally named for vaccinia, or the cowpox virus.

Variolation

The introduction of the virus of smallpox into a healthy person to produce immunity to the disease.

Wavelength

The distance between the peaks of a wave of radiant energy, such as light; usually measured in nanometers (billionths of a meter).

y-Intercept

The point on the y-axis of a graph at which the best-fit line crosses.

Yaba (Crazy medicine, Nazi speed)

Yaba is a combination of methamphetamine and caffeine, often used in a "chasing the dragon" method, or crushed then snorted, or mixed with solvent and injected. It is popular at raves and is illegal, because it contains methamphetamine, a Schedule II drug.