Flow Cytometry Terms
animal model – an animal similar to humans in its anatomy or physiology used in research in order to obtain information that can be used to estimate how humans may respond
CD8+ T-cells –- a type of lymphocyte that matures in the thymus. When activated, these cells develop into cytotoxic T lymphocytes (CTL) that are capable of directly killing tumor cells, virus infected cells and some parasites.
CD4+ T cells –- a type of lymphocyte that matures in the thymus. These cells are also called "helper" T cells because they produce factors that help other cells of the immune system to carry out their functions.
cytotoxic T lymphocytes (CTLs) – a specific type of T lymphocyte that destroys mutated or tumor cells.
dioxin – a general name for a large group of chemical compounds with similar structure. These compounds are made up of carbon, oxygen, hydrogen and chlorine atoms.
flow cytometer – an instrument used in medical and scientific research settings that can make rapid measurements and counts of cell samples
fluorescent marker - a substance that attaches to a specific type of protein on the interior or exterior of cell surfaces and contain a fluorochrome
fluorochrome – a fluorescent chemical that emits a specific color of light when illuminated by light
forward scatter – light reflected by cells at small angles (less than 90 degrees) and provides information about the size of the cell
granularity – the amount of granules within a cell
granule – particles in cells which contain chemicals used to destroy foreign substances and cells
granulocytes – immune system cells which contain granules
histogram – a graph representing the data produced by the flow cytometer. Both x- and y-axes indicate increasing brightness of fluorescence of the markers attached to the cells.
Human Immunodeficiency Virus (HIV) – a class of viruses that infect and destroy helper T cells of the immune system
immune system – the system that protects the body from foreign substances, cells, and tissues
immunotoxicant – a chemical that is harmful to the immune system
immunotoxicology – the study of substances that are harmful to the immune system
leukocytes – white blood cells
lupus – a disease caused by the mistaken attack of healthy body cells by the immune system
lymphocyte – a type of immune system cell associated with the lymph node system
macrophage – a type immune system cells which engulfs harmful foreign cells and substances
monocytes – a type of white blood cell which matures into a macrophage
mutate – undergo a significant change; with cells, DNA mutations often result in changes of protein production
non-immune control – mice that have not been exposed to dioxin or injected with tumor cells.
side scatter –- light reflected by cells at right angles (90 degrees) and provides information about the granularity of the cells
TCDD – 2,3,7,8-tetrachlorodibenzo-p-dioxin, the most potent chemical of the dioxin family of chemicals
thymus – a gland in the body that is involved with the development of the immune system; located in the upper torso area
vehicle control – mice that were injected with tumor cells but were not treated with dioxin. Instead they are injected with the liquid that dioxin was dissolved in (called the ‘vehicle’)
GCMS and Environmental Chemistry Terms
accelerated solvent extractor – a device which uses high temperature and pressure to dissolve and remove compounds that are stuck onto the air sampling resin and filters
column – a very small and thin tube through which a chemical mixture flows and is separated by gas chromatography.
chromatography – a process in which a chemical mixture, carried by a liquid or gas, is separated into components
computer model – predicted outcome made by using a computer to calculate mathematical equations used estimate patterns such as weather or wind direction
DDT- dichlorodiphenyldichloroethylene; an insecticide historically used in the United States to control mosquitoes and the spread of the disease malaria. DDT has been banned in the US since 1972 because of its persistence in the environment. However, DDT is still allowed for use internationally to control mosquitoes and malaria.
environmental chemistry – the study of the fate and transformation of chemicals in the environment
fragment ion – an ion which is only a fragment of the whole molecule after passing through the ion source of the mass spectrometer
GCMS – Gas Chromatography - Mass Spectrometry
ion – a charged atom or molecule, can be positive or negatively charged
mass spectrum –the range ions separated according to their mass; the data output from the GCMS
microliter – one-millionth of a liter, 0.000001 liter
molecular ion – an ion which has not broken into fragments after it passed through the ion source in the mass spectrometer. This molecular ion reflects the molecular mass of the original compound as it passed through the GCMS.
organic compound – a chemical containing carbon and hydrogen
retene – an organic compound that is often created by the burning of plant material
retention time – the time it takes for a compound to travel through the gas chromatography column
solvent – usually liquid substance capable of dissolving one or more other substances
standard – a known amount, used to calibrate an instrument
troposphere – the lowest part of the earth's atmosphere which extends from the surface of the earth to the bottom of the stratosphere, approximately 5-9 miles high
volatile – readily evaporates to the gas phase at a relatively low temperature
Microarray and Developmental Toxicology Terms
animal models – animals with biology similar to humans. Animal models are used to study the effects of toxic substances, diseases, or treatments because they respond similar to humans.
control treatment – in an experiment, the control treatment undergoes the exact same conditions as the experimental treatment except for the one factor being tested.
developmental biology – the study of the processes by which organisms grow and develop from a fertilized egg to a mature adult.
developmental toxicology – the study of substances that disrupt or disturb an organism’s development.
developmental toxin – a substance that harms an organism’s development.
DNA – deoxyribonucleic acid – a double-stranded helix structure, usually found in the cell nucleus, that contains hereditary material and instructions for cell and organism structure and function.
experimental treatment – in an experiment, the experimental treatment is exposed to one factor. Any differences between the experimental treatment and the control treatment are likely to be caused by factor that was tested.
gene – a section of DNA that contains instructions for a structure (protein) or process in an organism.
gene expression – a combination of genes that are turned off or turned on in response to a specific condition.
microarray - A two-dimensional grid of DNA genes or gene fragment spots, usually arranged on a glass slide or silicone wafer. A typical microarray contains 10,000-200,000 microscopic DNA spots.
mRNA – messenger ribonucleic acid – a single-stranded structure which carries the instructions from DNA to ribosomes (protein making structures) in cells
vertebrate – an animal with a spinal column
zebrafish - Danio rerio, tropical freshwater fish originally found in slow moving streams and rice paddies in India