Glossary

acaricide - a chemical used to kill mites and ticks.
acute - having a rapid onset and following a short but severe course: acute disease.
allergen - substance (such as mold) that can cause an allergic reaction.
analogue - - a chemical compound that is structurally similar to another but differs slightly in composition; often used in immunochemical work to substitute a non-hazardous test component for its hazardous (target) counterpart, providing safety without compromising the assay objectives.
analyte - the substance to be detected; the target compound in an immunoassay.
antibody - a protein substance produced in blood or tissues in response to a specific foreign substance, such as a bacterium or toxin.
antigen - a substance that when introduced into the body stimulates the production of an antibody. Antigens include toxins, bacteria, viruses, pesticides, fungii, and chemicals.
antiserum - (plural, antisera) human or animal serum containing antibodies that are specific for one or more antigens.
applicator - a person applying potentially harmful chemicals, such as pesticides, herbicides, fungicides, fertilizers, and certain industrial chemicals.
aromatic solvents - those solvents containing the hydrocarbon benzene or a related organic compound.
assay - qualitative, quantitative or semi-quantitative analysis of a substance to determine its components.

BEM - biological exposure monitoring or human exposure monitoring. A testing program to detect changes in the levels of pesticides, toxins or other contaminants to which individuals have been exposed. Often measured indirectly by testing the level of metabolites remaining in a person�s system, since the initial substance may break down fairly rapidly.
b-site or beta site - a secondary test location used for evaluating a product just prior to broad commercial application. Typically beta sites are selected customers with known interest in the product and a willingness to share their evaluations confidentially for confirmation of results or for further refinement.
biocide - substance or chemical that kills organisms such as molds.
biomarker - a specific trait, often expressed as an enzyme or protein, used to measure or indicate the presence of a related chemical or a genetic event, or to measure or indicate the effects or progress of a disease or condition.
Bt (Bacillus thuringiensis) - a type of bacteria commonly sprayed by organic farmers as a natural insecticide. When ingested by certain insects, the bacteria secretes an endotoxin that ruptures the insect's mid gut, causing it to die. Different forms of Bt are effective against insects of the orders Lepidoptera (a group of certain caterpillars, moths and butterflies), Coleoptera (beetles, e.g., Colorado potato beetles), and Diptera (flies and mosquitoes). By the nature of its action, Bt is believed to be harmless to mammals, birds, fish and certain beneficial insects. Through genomic research, seed breeders are able to insert the gene sequence giving rise to the endotoxin into the DNA of certain plants, such as corn and cotton, producing a natural insecticide.

cassette - in connection with lateral flow immunoassays, a format that includes both a multi-layer membrane and a protective plastic housing. Sample extract is applied with a dropper to a "well" or opening in the cassette and drawn laterally across the membrane by capillary action. Results are "read" in a test zone on the cassette by the presence or absence of certain colored lines. See also "lateral flow membrane assay".
chromatography - any of various techniques for the separation and measurement of complex mixtures that rely on the differential affinities of substances for certain gases or liquid mobile media and for a stationary adsorbing medium through which they pass, such as paper, gelatin, magnesia or a form of silica.
chromogen - a color-generating reagent.
chronic - lasting for a long period of time or marked by frequent recurrence, as certain diseases or illnesses.
competitive assay - a form of immunoassay in which residues in the sample compete with known amounts of the test analyte for a limited number of antibody binding sites on the test media. The outcome of the competition is visualized with a color development reaction. In all competitive immunoassays, the sample concentration is inversely proportional to color development: darker color = lower concentration of the target analyte; lighter color = higher concentration of the target analyte.
conjugate - a reagent prepared by chemically coupling an enzyme or other protein with an analyte. See enzyme conjugate.
cross-reactivity - the presence or extent of reaction between an antigen and an antibody that was generated against a technically different but structurally similar antigen.
Cry1Ab, cryIII, etc. - the crystalline form of a Bt endotoxin. "Cry" is used to denote the protein; "cry" is used to denote the gene. Over 50 Cry proteins have been isolated from 14 different Bt subspecies.
cultivar - a horticultural race or variety of a plant that has originated and persisted only under cultivation.
Cyanobacteria - A division of bacteria formerly known as blue-green algae; they create their own energy through photosynthesis.

dipstick - in connection with lateral flow immunoassays, a format that employs a multi-layer, coated membrane, without an outer shell, which is dipped directly in a vial of sample extract to initiate operation of the test. The extract is drawn upward through the test zones by capillary action. Results are "read" through absence or presence of certain colored bands toward the top of the membrane.

EIA (enzyme immunoassay) - an immunoassay using a color-changing enzyme-substrate system for indicating results.
ELISA (enzyme-linked immunosorbent assay) - a form of EIA using a solid phase for separating bound from free enzyme conjugate.
EPA - Environmental Protection Agency.
endocrine - the secretion of an endocrine gland; a hormone.
endocrine disruptor - a substance which interferes with the secretion of one or more specific hormones.
endotoxin - a poisonous substance found within a cell, usually in the outer membrane. Originally contained in bacteria, gene research has discovered how to implant certain endotoxins in the genetic makeup of other organisms such as plants. For example, the endotoxin secreted by the bacteria Bacillus thuringiensis is now included in the genome of certain varieties of corn and cotton plants to provide a natural defense against the European corn borer and the cotton bollworm.
enzyme - any of numerous proteins produced by living organisms and functioning as biological catalysts in a cell. In general, these biochemical reactions would not occur if the enzyme is not present.
enzyme conjugate - the covalent attachment of an enzyme with another molecule, for example, a pesticide. Used for interaction with test samples to detect or measure presence or concentration of a specific substance.
expression - the tangible result of particular gene or gene sequence, in the form of an enzyme or other protein contained in the host organism.

fungi - organisms such as slime molds, mushrooms, smuts, rusts, mildews, molds, stinkhorns, puffballs, truffles and yeasts. All are classified in this kingdom because they absorb food in solution directly through their cell walls and reproduce through spores. Mold spores waft through the indoor and outdoor air continually. When mold spores land on a damp spot indoors, they may begin growing and digesting whatever they are growing on. Molds can grow on virtually any organic substance, providing moisture and oxygen are present. It is estimated that more than 1.5 million species of fungi exist. None conduct photosynthesis.
fungicide - a substance or chemical used to kill fungi.

GC (Gas Chromatography) - an analytical method in which a sample is vaporized and injected into a carrier gas (called the mobile phase; usually helium) moving through a column. The inner surface of the column is coated with a stationary phase. The vaporized sample is separated into its component compounds according to their affinity for the stationary phase. The components are identified by matching the time they are retained by the stationary phase to the retention times of known standards. The quantity of a particular compound in the mixture is determined by comparing detector response to the response to known standards. Identification of unknown compounds is only possible if the detector used is a mass spectrometer. The technique can require extensive cleanup and preparation of the sample, the use of costly equipment, and operation by a highly trained technician.
GE (Genetically Engineered) Foods - Foods in which ingredients contain genetically modified organisms.
GMOs (Genetically Modified Organisms) - food ingredients in which the host DNA has been altered by insertion of gene sequences from another organism. These modifications are made to reduce the cost or improve the effectiveness of agricultural chemical applications (input traits) or to enhance the quality, appearance or value of resulting food products (output traits).

HEPA - high-efficience particulate air.
herbicide - A chemical used to kill or control the growth of plants. Some herbicides (such as synthetic triazines) selectively kill broad-leaved plants while leaving grass-leafed plants (i.e., cereal crops) unharmed. Other herbicides, such as paraquat, kill all plants.
hormone - a substance produced by one tissue and conveyed by the bloodstream to effect physiological activity, such as growth or metabolism. Any of various similar substances found in plants and insects that regulate development.
hormone mimic - a foreign substance that binds with a hormone receptor or otherwise disrupts the production of natural levels of hormones within the endocrine system.
hormone receptor - a molecular site within the bloodstream or body organ which binds with a specific hormone.
HPLC (High Performance Liquid Chromatography) - an analytical method in which a sample is injected into a stream of liquid (called the mobile phase; usually a mixture of water and an organic solvent) moving through a column. The inner volume of the column is packed with a stationary phase. The sample is separated into its component compounds according to their affinity for the stationary phase. The components are identified by matching the time they are retained by the stationary phase to the retention times of known standards. The quantity of a particular compound in the mixture is determined by comparing detector response to the response to known standards. Identification of unknown compounds is only possible if the detector used is a mass spectrometer. The technique can require extensive cleanup and preparation of the sample, the use of costly equipment, and operation by a highly trained technician.
hypersensitivity - Great or excessive sensitivity.

IAQ - Indoor Air Quality.
immunoassay - an analytical test to measure or detect a substance using antibody-antigen reactions. A technique that makes use of the specific binding between an antigen and its related antibody to identify or quantify a substance in a sample.
immunochemical - pertaining to chemical reactions involving antigen-antibody relationships.
immunodiagnostic - a test or procedure for identifying or determining the nature and cause of a disease through immunoassay techniques.
immunogen - an antigen capable of inducing the production of specific antibodies.
insecticide - a chemical used to kill insects. Insecticides are a form of pesticide.



lateral flow membrane assay - a form of immunoassay in which certain reagents are dried in specific zones on a porous membrane of one or more layers. A liquid sample is applied to one end of the membrane and drawn through the reagent zones by capillary action, usually assisted by an absorbent pad at the opposite end of the membrane. Typically a colored "control line" close to the absorbent pad indicates whether the test ran successfully. Results of the test are indicated by the presence or absence of one or more additional "test lines" that are expected between point of sample application and the control line. May be in either cassette or dipstick format. Usually requires no additional reagents.

matrix - the material in which a sample is contained, such as water, soil or plant material, potentially including components other than the sample target.
membrane - a thin, soft pliable sheet or layer used to filter or transport a liquid or gas for test purposes. Usually differentiated by pore size and composition. In lateral flow immunoassays, the membrane is often nitrocellulose, sometimes built up of several layers, and often supported by a more rigid backing.
metabolism - the functioning of a specific substance within the living body. In metabolism some substances are broken down to yield energy for vital processes while other substances, necessary for life, are synthesized.
metabolite - a derivative substance produced by metabolism. One of the altered substances resulting from the metabolic process within a living organism. A breakdown product of a parent compound.
microwell plates - polystyrene strips linked together in a rectangular 8 x 12 well format (plate) for ease of use in performing multiple tests through techniques such as EIA and ELISA.
microwell strips - a linked series of small, separate polystyrene test wells (each approximately the size and shape of a pencil eraser) used for performing analyses such as EIA and ELISA.
microcystin toxin - a poisonous substance secreted by certain "blue-green algae," or cyanobacteria. Microcystins are considered toxic to humans at elevated levels; the World Health Organization (WHO) has established a limit of 1 ppb microcystin in drinking water.
mg - milligram. One one-thousandth of a gram. A measure of weight.
ml - milliliter. One one-thousandth of a liter. A measure of volume, usually of fluids.
mVOC - microbial volatile organic compound, a chemical made by a mold which may have a moldy or musty order.
ml - milliliter. One one-thousandth of a liter. A measure of volume, usually of fluids.

nematicide - A chemical used to kill nematodes, which are a phylum of elongated cylindrical worms parasitic in animals or plants, or free-living in soil or water.

OSHA - Occupational Safety and Health Administration.
organophosphates - any of several organic compounds containing phosphorous, some of which are used as pesticides and fertilizers, primarily relating to the organophosphorous class of insecticides.

pathogen - an agent that causes disease, especially a living microorganism such as a bacterium, virus or fungus.
pesticide - a chemical or other agent used to destroy pests. Commonly includes insecticides, herbicides, fungicides, and nematicides.
polymerase chain reaction (PCR) - a method for creating millions of copies of a particular segment of DNA. If a scientist needs to detect the presence of a very small amount of a particular DNA sequence, PCR can be used to amplify the amount of that sequence until there are enough copies available to be detected.
PPB or ppb - parts per billion. A term of measurement of the relative concentration of one substance within a carrier medium such as water, blood, serum, urine or an extract buffer. e.g., one part DDT per billion parts of water or 10^-9 grams of DDT per gram of water.
PPE - personal protective equipment.
PPM or ppm - parts per million. For example, 10^-6 grams per gram.


reagent - a substance used in a chemical reaction to detect, measure, examine or produce other substances.
remediate - fix.
residue methods - analytical techniques involving an abstractive chemical or physical process such as evaporation, distillation, filtration, chromatography or immunoassay.

sandwich assay - a form of ELISA in which analyte in a sample becomes "sandwiched" between a specific antibody bound to a solid phase and a second antibody labeled with an enzyme. The enzyme causes production of a colored product after addition of a substrate. In contrast to a competitive assay, sample concentration is directly proportional to color development: darker color = higher concentration of the target analyte in the sample; lighter color = lower concentration of the target analyte in the sample.
sensitization - repeated or single exposure to an allergen that results in the exposed individual becoming hypersensitive to the allergen.
serological - the characteristics of a disease or an organism shown by study of blood serums.
solid phase - an insoluble substance used in any immunoassay to separate bound from free reagents; the substance to which antibodies or antigens may be attached.
spore - molds reproduce by means of spores. Spores are microscopic; they vary in shape and size (2-100 micrometers). Spores may travel in several ways�they may be passively moved (by a breeze or waterdrop), mechanically disturbed (by a person or animal passing by), or actively discharged by the mold (usually under moist conditions or high humidity).
substrate - a reagent which, when it reacts with the enzyme in an EIA, causes a chromogen to produce a measurable color change.

target (analyte) - in immunoassays, the substance which is intended to be discovered and measured.
toxin - a poisonous substance that is produced by living cells or organisms and is capable of causing disease or other measurable pathological effect.
transgenic - containing genes transferred from species to another. Having altered genetic makeup, often resulting in different physical and developmental characteristics.

tubers - swollen, fleshy, usually underground stems, such as potatoes, bearing buds from which new plant shoots arise.