| DFA | Direct Fluorescent Antibody |
|---|---|
| DFA | direct fluorescent antibody; discriminant function analysis; dorsiflexion assistance |
| ACA | abnormal coronary artery; acrodermatitis chronica atrophicans; acute cerebellar ataxia; adenocarcino... |
| DAT | delayed-action tablet; dementia Alzheimer's type; dental aptitude test; diacetylthiamine; diet as to... |
| DC | daily census; data communication; data conversion; decrease; deep compartment; Dental Corps; deoxych... |
| staining | The use of a dye, reagent, or other material for producing colouration in tissues or microorganisms for microscopic examination. (12 Dec 1998) |
|---|---|
| negative staining | Microscopic technique in which the object stands out against a dark background of stain. For electron microscopy the sample is suspended in a solution of an electron dense stain such as sodium phosphotungstate and then sprayed onto a support grid. The stain dries as structureless solid and fills all crevices in the sample. When examined in the electron microscope the sample appears as a light object against a dark background. Quite fine structural detail can be observed using negative staining and it has been used extensively to study the structure of viruses and other particulate samples. (18 Nov 1997) |
| dispersion staining | <microscopy> A procedure involving central or annular stops in the objective back focal plane to induce coloured images of transparent particles mounted in liquids with indices matching the particle at a wavelength in the visible. The particle and liquid should possess very different dispersion curves for best colours. (05 Aug 1998) |
| optical staining | <microscopy> Producing colour in the microscopical image so as to differentiate one part of the object from another. One way is by use of Rheinberg filters. Another is to use polarized light on an anisotropic specimen. Another important method is by dispersion staining. (05 Aug 1998) |
| auramine O fluorescent stain | <technique> A rapid and accurate technique for Mycobacterium tuberculosis, using auramine O-phenol and a methylene blue counterstain. (05 Mar 2000) |
| green fluorescent protein | <protein> A protein found in jellyfish which fluoresces, or glows green visible light when excited by UV light with a wavelength of 395 nanometres. It can function as a biological marker when attached to other proteins. The structure of the protein is cylindrical with the glowing component, an amino acid complex called a fluorophore, in the middle of it. (09 Oct 1997) |
| microscope, fluorescent | A microscope equipped to examine material that fluoresces under ultraviolet (uv) light. (12 Dec 1998) |
| Kasten's fluorescent Feulgen stain | <technique> A fluorescent modification of the Feulgen stain, utilizing any one of a variety of fluorescent basic dyes to which SO2 is added; the brilliant fluorescence makes this method unusually sensitive and adaptable to cytofluorometric quantification of DNA. (05 Mar 2000) |
| Kasten's fluorescent PAS stain | <technique> A fluorescent modification of the periodic acid Schiff stain for polysaccharides which uses one of Kasten's fluorescent Schiff reagents. (05 Mar 2000) |
| Kasten's fluorescent Schiff reagents | Fluorescent analogues of Schiff's reagent which are fluorescent basic dyes lacking acidic side groups and containing one or more primary amine groups; used in cytochemical detection of DNA in Kasten's fluorescent Feulgen stain, polysaccharides in Kasten's fluorescent PAS stain, and proteins in the ninhydrin-Schiff stain; such analogues include acriflavine, auramine O, and flavophosphine N. (05 Mar 2000) |
| fluorescent | Having the ability to emit light of a certain wavelength when activated by light of another wavelength. (09 Oct 1997) |
| fluorescent dyes | Dyes that emit light when exposed to 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. They are used as markers in biochemistry and immunology. (12 Dec 1998) |
| fluorescent in situ hybridization | See FISH. (12 Dec 1998) |
| fluorescent label | A molecule which fluoresces and can be attached to a probe molecule that does not fluoresce. (09 Oct 1997) |
| fluorescent microscope | <instrument> A microscope equipped to examine material that fluoresces under ultraviolet (UV) light. (12 Dec 1998) |