| regressive staining | A type of staining in which tissues are overstained and the excess dye is then removed selectively until the desired intensity is obtained. (05 Mar 2000) |
|---|---|
| progressive staining | A procedure in which staining is continued until the desired intensity of colouring of tissue elements is attained. (05 Mar 2000) |
| homogeneously staining region | <molecular biology> A region on a chromosome which, when stained, is uniform in appearance. (Normally, a stained chromosome shows a banding pattern.) Homogeneously staining regions contain multiple copies of a single gene. (09 Oct 1997) |
| silver staining | The use of silver, usually silver nitrate, as a reagent for producing contrast or colouration in tissue specimens. (12 Dec 1998) |
| 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) |
| Mallory's triple stain | <technique> A method especially suitable for studying connective tissue; sections are stained in acid fuchsin, aniline blue-orange G solution, and phosphotungstic acid; fibrils of collagen are blue, fibroglia, neuroglia, and muscle fibres are red, and fibrils of elastin are pink or yellow. Synonym: Mallory's aniline blue stain, Mallory's triple stain. (05 Mar 2000) |
| Ehrlich's triple stain | <technique> A mixture of indulin, eosin Y, and aurantia. (05 Mar 2000) |
| triple | 1. Consisting of three united; multiplied by three; threefold; as, a triple knot; a triple tie. "By thy triple shape as thou art seen." (Dryden) 2. Three times repeated; treble. See Treble. 3. One of three; third. Triple crown, the crown, or tiara, of the pope. See Tiara. Triple-expansion steam engine, a compound steam engine in which the same steam performs work in three cylinders successively. Triple measure, a measure of tree beats of which first only is accented. <mathematics> Triple ratio, that time in which each measure is divided into three equal parts. Triple valve, in an automatic air brake for railroad cars, the valve under each car, by means of which the brake is controlled by a change of pressure in the air pipe leading from the locomotive. Origin: L. Triplus; tri- (see Tri-) + -plus, as in duplus double: cf. F. Triple. See Double, and cf. Treble. Source: Websters Dictionary (01 Mar 1998) |
| triple bond | A covalent bond resulting from the sharing of three pairs of electrons; e.g., HC≡CH (acetylene). (05 Mar 2000) |
| triple DNA | <molecular biology> A variation of DNA, in which there is a third strand of nucleotides binding to the first two by specific base pairing. (14 Nov 1997) |
| triple helix | The superhelix formed (right-handed) from three individual collagen helices (each being left-handed). (05 Mar 2000) |
| triple phosphate | Magnesium ammonium phosphate, MgNH4PO4, a crude phosphate fertiliser product from phosphate rock and phosphoric acid. Trisodium phosphate, Na3PO4;used to emulsify fats, oil, and grease; an irritant. (05 Mar 2000) |