Absorption Spectrum: a diagram that depicts the wavelengths of (light) that are absorbed by a pigment. (Brooker, 155) The characteristic plot of “wavelength” versus ‘intensity’ of (light) that has been absorbed by a given substance. (Lawrence)

Biological Measurements: annotation used to indicate the size or magnitude of something that was determined by comparison to a standard. (NCIt)

Centimorgan: refers to the distance between two gene “loci” determined by the frequency with which “recombination” occurs between them. Two loci are said to be one centimorgan apart if recombination is observed between them in 1% of “meioses.” (GeneReviews) One centimorgan equals a one percent chance that a “marker" on a “chromosome” will become separated from a second marker on the same chromosome due to “crossing over" in a single "generation." It translates to approximately one million “base pairs” of “DNA sequence” in the “human genome.” (NHGRI) Editor's note - the centimorgan was discovered by and named after American geneticist Thomas Hunt Morgan. Also referred to as ‘a unit of linkage.’

Concentration: the amount of "solute" per unit volume of a solution. (Oxford)

Magnification: the ratio between the size of an image produced by a microscope and its actual size. (Brooker, 61)

Osmolarity: the "concentration" of body fluids measured in terms of the amount of dissolved substances per unit mass of water. (OxfordMed)

R1 Values: ratios which measure how far a particular chemical moves during "paper chromatography." (Hunt, 292)

Resolution: the degree to which individual details can be distinguished by the human eye. (OxfordMed) A measure of the clarity of an image. The ability to to observe two adjacent objects as distinct from one another. (Brooker, 62) The size of the smallest element that can be separated from neighboring elements. (NCIt)

Units of Volume: units used to measure a determinate quantity or amount of a substance. (Oxford)

Liter: a metric unit of capacity, formerly defined as the volume of 1 kilogram of water under standard conditions, now equal to 1,000 cubic centimeters. (Oxford) 

Microliter: one millionth of a liter. (Symbol: μl) (Oxford)

Milliliter: one thousandth of a liter (.0002 pint). (Oxford)

Pint: a unit of liquid or dry capacity equal to one half of a quart. (Oxford)

Quart: a unit of liquid capacity equal to a quarter of a gallon or two pints, equivalent in the US to approximately 0.94 liter and in Britain to approximately 1.13 liters. (Oxford)

Biological Staining and Labeling: the marking of biological material with a “dye” or other “reagent” for the purpose of identifying and quantitating components of “tissues,” cells or their extracts. (MeSH)

Coloring Agents: chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in inks; paints; and as indicators and reagents. (MeSH)

Dyes: chemical substances that are used to stain and color other materials. The coloring may or may not be permanent. Dyes can also be used as therapeutic agents and test reagents in medicine and scientific research. (NCIt)

Fluorescent Dyes: agents that 'emit' "light" after excitation by light. The "wave length" of the emitted light is usually longer than that of the ‘incident' light. ‘Fluorochromes’ are substances that cause "fluorescence" in other substances, i.e., dyes used to mark or label other compounds with "fluorescent tags." (MeSH)

Negative Staining: the technique of washing tissue specimens with a concentrated solution of a 'heavy metal salt' and letting it dry. The specimen will be covered with a very thin layer of the metal salt, being excluded in areas where an adsorbed “macromolecule” is present. The macromolecules allow "electrons" from the beam of an "electron microscope" to pass much more readily than the heavy metal; thus, a reversed or negative image of the molecule is created. (MeSH)

Prussian Blue Reaction: the reaction of 'potassium ferrocyanide’ with 'ferric iron' to yield a dark blue 'precipitate' at the sites of the ferric iron. Used to determine ferric iron in tissues, particularly in the diagnosis of disorders of iron metabolism. (MeSH)

Radioisotopic Labeling: a laboratory procedure that results in the incorporation of a “radioactive” “isotope” into a molecule of interest. (NCIt) Any compound that has been joined with a radioactive substance. (NCI1) Also referred to as ‘radiolabeled.’

Shadowing: the technique of spraying a tissue specimen with a thin coat of a heavy metal such as platinum. The specimen is sprayed from an oblique angle, which results in the uneven deposition of the coating. The varying thicknesses create a shadow effect and give a three-dimensional appearance to the specimen. (MeSH)

Silver Staining: the use of “silver,” usually 'silver nitrate,' as a reagent for producing "contrast" or coloration in tissue specimens. (MeSH) A technique for demonstrating “fungi” in tissue sections. (NCIt)

Stain: a dye or other coloring material that is used in microscopy to make structures visible. (NCIt)

Clinical Study: research conducted with human subjects or on material of human origin in which an investigator directly interacts with human subjects; includes development of new technologies, study of mechanisms of human diseases, therapy, clinical trials, epidemiology, behavior, and health services research. (NCIt)

Clinical Research Associate: a person who is employed by a study sponsor or by a ‘contract research organization,’ operates independently from the clinical study site and functions as a monitor, and/or auditor, and/or a project director within a particular trial or institution. (NCIt)

Clinical Researcher: health professional who works directly with patients, or uses data from patients, to do research on health and disease and to develop new treatments. Clinical researchers may also do research on how health care practices affect health and disease. (NCI1)

Clinical Trial: a scientifically controlled study of the safety and effectiveness of a therapeutic agent (as a drug or vaccine) using consenting human subjects. (GHR) Research study that involves people. Prospectively assigns human participants or groups of humans to one or more health-related interventions to evaluate the effects on health outcomes. Interventions include, but are not restricted to, drugs, cells and other biological products, surgical procedures, radiologic procedures, devices, behavioral treatments, process-of-care changes, and preventive care. (NCIt) These studies test new methods of screening, prevention, “diagnosis,” or treatment of a disease. (Includes phases that are) part of the clinical research process, that answers specific questions about, whether treatments that are being studied work and are safe. (NCI1)

Phase I Clinical Trial: tests the best way to give a new treatment and the best dose. (NCI1)

Phase II Clinical Trial: tests whether a new treatment has an effect on the disease. (NCI1)

Phase III Clinical Trial: compares the results of people taking a new treatment with the results of people taking the standard treatment. (NCI1)

Phase IV Clinical Trial: done, using thousands of people after a treatment has been approved and marketed, to check for side effects that were not seen in the phase III trial. (NCI1)

Diffraction Pattern: a pattern of scattering. If a substance has a 'repeating' structure, the diffraction pattern is mathematically related to the structural arrangement of the "atoms" causing the scattering. (Brooker, 216)

ELISA Technique: enzyme linked 'immunoabsorbant assay.' (Lawrence)  A sensitive method used by biochemists for measuring the concentration of a particular substance. The more of the substance present, the more "antibody" complexes are formed. (Indge, 93) 

Ex Vivo: outside of the living body. Refers to a medical procedure in which an organ, cells, or tissue are taken from a living body for a treatment or procedure, and then returned to the living body. (NCI1)

Gel Electrophoresis: test commonly used to separate compounds by their component parts, 'molecular weight' or electric charge. The procedure uses an “agarose” gel as the stationary media to conduct electricity and house the samples to be tested. (Norman Lab, 93) Arranged so that a direct current is passed through the medium. As a result, each of the substances to be separated will have a different charge and will move at a different rate. (Indge, 93)

In Silico: research performed on a computer or via computer simulation. (HGPIA)

In Situ: in its original place. For example, in 'carcinoma in situ,' abnormal cells are found only in the place where they first formed. They have not spread. (NCI1)

In Vitro: the study of cell functions outside of the cell (literally 'in glass,') such as in a glass "test tube." (Brooker, 73) In the laboratory (outside the body). The opposite of "in vivo." (NCI1) In biology and “medicine” … the duplication of processes that would normally occur within a living organism in artificial conditions outside the body in a culture dish or test tube. (Bynum, 292)

In Vivo: in the body. The opposite of in vitro. (NCI1) Literally, within the living organism. Applied to processes taking place within the body rather than artificially outside it. (Bynum, 292)

Laboratory: facility equipped to carry out investigative procedures. (MeSH) Facility competent to conduct scientific experiments, observations, tests, investigations, and/or to manufacture chemicals or medical products. An organization with the capability and competency to perform scientific research, experiments and measurements. (NCIt) Also referred to as ‘lab.’

Laboratory Director: a person who plans, organizes, coordinates and oversees the overall operation of laboratory activities. The laboratory director establishes policies and procedures that govern the utilization of community laboratory services, and ensures that the laboratory and support personnel receive the appropriate training associated with the work involved. (NCIt)

Research Associate: a person who is an assistant or subordinate to another professional, e.g. research associate functioning under the general supervision of the appointed investigator. (NCIt)

Laboratory Chemicals: chemicals necessary to perform experimental and/or investigative procedures and for the preparation of drugs and other chemicals. (MeSH)

Buffer: chemical system that functions to control the levels of specific “ions” in “solution.” When the level of hydrogen ions in solution is controlled, the system is called a ‘pH buffer.’ (MeSH)

Culture Media: any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as 'differential media,' 'selective media,' 'test media,' and 'defined media.' Solid media consist of liquid media that have been solidified with an agent such as “agar” or “gelatin.” (MeSH) Also referred to as 'media.'

Agar: a “polysaccharide” obtained from seaweed. It is important in making solid media for the culture of microorganisms. After heating and mixing with various nutrients, it cools to form a stiff jelly on which microorganisms such as bacteria and fungi may be grown. (Indge, 9)

Agarose Gel: an “electrophoresis” gel composed of agarose dissolved in an aqueous buffer. (NCIt)

Conditioned Culture Media: media containing biologically active components obtained from previously cultured cells or tissues that have been released into the media substances affecting certain cell functions. (MeSH)

Serum-Free Culture Media: culture media free of 'serum' proteins but including the minimal essential substances required for cell growth. This type of medium avoids the presence of extraneous substances that may affect cell proliferation or unwanted activation of cells. (MeSH)

Gelatin: a product formed from skin, white connective tissue, or “bone”  “collagen.” It is used as a protein food (modifier), "plasma" substitute, 'suspending agent' in pharmaceutical preparations, and in the manufacturing of capsules. (MeSH)

Indicators: substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical (analysis). (MeSH)

Reagents: any pure chemical, mixture or solution supplied for chemical analysis or “synthesis.” (Hunt, 299) Compounds that detect the presence of other specific compounds. (Norman, 27) Also referred to as ‘indicator reagents.’

Benedict’s Reagent: indicator solution for "reducing sugars." (Norman, 33) The deep-blue reagent contains copper ions with citrate ions in an “alkaline” solution.  (When) a reducing sugar reduces the reagent to copper oxide, the blue color fades and a reddish-brown precipitate forms. (Hunt, 52)

Biuret Reagent: indicator solution for proteins. (Norman Labs, 26) Used in a test to detect proteins. The procedure is to add 'sodium hydroxide' to  a test sample followed by a few drops of 'copper sulfate' solution. The solution turns mauve if protein is present. Test is actually detecting “peptide bonds.” (Hunt, 56)

Diagnostic Reagents and Test Kits: commercially prepared reagent sets, with accessory devices, containing all of the major components and literature necessary to perform one or more designated diagnostic tests or procedures. They may be for laboratory or personal use. (NCIt)

Lugol’s Iodine: indicator solution for "starch." (Norman Labs, 26) 'Potassium triiodide.’ Coloring agent. (MeSH) Also referred to as ‘Lugol’s solution.’

Ninhydrin: indicator solution for “amino acids.” (Norman Labs, 26) Reagent toxic to skin and "mucus membrane." It is used in 'chemical assay' for peptide bonds. (MeSH)

Potassium Ferrocyanide: indicator solution used in experiments to test for the presence of copper. (Norton Labs, 26, 31)

Reducing Agents: materials that add an electron to an element or compound. ‘Reducing’ refers to oxidation-reduction, not body weight. (MeSH)

Reducing Sugar: a sugar which is able to produce a positive result, an orange-red precipitate, when heated with Benedict’s solution. In chemical terms, a reducing sugar contains either a free 'aldehyde' group or a free 'keytone' group. It is the presence of one or other of these chemical groups that enables it to reduce Benedict’s solution. All ”monosaccharides” and most “disaccharides” are reducing sugars. “Sucrose” is an exception. It is a non-reducing sugar. (Indge, 230)

Sudan IV: indicator solution for "lipids." (Norman Labs, 26) Coloring agent. Scarlet ointment. (MeSH) Also referred to as ‘scarlet red.’

Laboratory Glassware: low expansion, temperature resistant glass for chemistry and life science applications. (Corning, Technical Resources)

Beaker: glass container used to measure out liquids in a given range. (Norman, 33) Spout facilitates pouring. 'Graduated' (marked with units of measurement) to indicate their approximate content. (Corning, Life Sciences Catalog)

Flask: graduated to show approximate capacity. Some have seated a bent, removable (piece) in a grommet (ring of rubber or plastic). Should the flask be upset, the grommet acts as a shock absorber. The neck is fit for rubber stoppers. (Corning, Life Sciences Catalog)

Graduated Cylinder: glass container used to measure out liquids in a given range. (Norman, 33) (Often) numbered both up and down. Metric. (Often) supplied with ‘polyethylene’ bumper guards. (Corning, Life Sciences Catalog)

Storage Bottles: reusable storage bottles designed for heavy duty storage of reagents, 'sterile tissue' culture media, biological fluids and other aqueous and non-aqueous solutions. (Corning, Life Sciences Catalog)

Test Tubes: glass containers used to mix and contain specific samples of material being tested. (Norman Labs, 33)

Microarray: a piece of glass or plastic on which different samples have been affixed at separate locations in an ordered manner thus forming a microscopic array. The samples are usually “DNA fragments” but may also be antibodies, other proteins, or tissues. (NCIt)

Microcentrofuge: used for “nucleic acid” and protein separations. Includes a digital control interface. (Corning, Life Sciences Catalog)

Microscope: an optical instrument that uses a combination of lenses to produce magnified images of very small objects. (NCIt) The resolution of an electron microscope is much higher than that of a light microscope (Kolb, 151)

Electron Microscope: works by projecting a beam of electrons through a very thin slice of tissue. The varying structure of the tissue scatters the beam onto a reflective surface where it leaves an image (or ’shadow’) of the tissue. If the tissue is stained with substances that reflect electrons, very fine structural details can be observed. (Kolb, 151)

Scanning Electron Microscopy: a type of electron microscopy that utilizes an electron beam to produce an image of the three-dimensional surface of biological samples. (Brooker, 63)

Transmission Electron Microscopy: (features) a beam of electrons transmitted through a biological sample. (Brooker, 62)

Paper Chromatography: a technique used to separate individual substances from a mixture. (Indge, 60) Uses a ‘stationary phase’ ('chromatography paper') to separate compounds based on their “solubility” in the solvent and their molecular weight. Solvents used depend on the specific experiment and thus may be “hydrophobic” or “hydrophilic depending on the sample compound you want to separate. (Normal Lab, 94)

Radionuclide Scanning: a procedure that produces pictures of structures inside the body, including areas where there are "cancer" cells. Used to diagnose, stage, and monitor disease. A small amount of a "radioactive" chemical (‘radionuclide’) is injected into a vein or swallowed. Different radionuclides travel through the blood to different organs. A machine with a special camera moves over the person lying on a table and detects the type of radiation given off by the radionuclide. A computer forms an image of the areas where the radionuclide builds up. These areas may contain cancer cells. (NCI1) Also referred to as ‘scintigraphy.’

Spectrophotometry: uses a distinct wavelength of radiant energy to measure the amount of absorbance by "solutes" in solutions. Also used to measure the amount of light transmitted through a solution. (Norman Labs, 95)