| TD | the time required to double the number of cells in a given population; thermal death time |
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| VVDL | venovenous double-lumen [catheter] |
| XX | double strength; female chromosome type |
| DBPCFC | Double-blind placebo-controlled food challenge |
| silver stain | <technique> Any of a variety of stain's (e.g., Bielschowsky's, Gomori's silver, impregnation stain's) which employ alkaline silver nitrate solutions to stain connective tissue fibres (reticulin, collagen), calcium salt deposits, spirochaetes, neurological tissue, and nucleolar organiser regions. (05 Mar 2000) |
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| Nakanishi's stain | <technique> A method for vital staining of bacteria in which a slide is treated with hot methylene blue solution until it acquires a sky-blue colour, after which a drop of an emulsion of the bacteria is put on the cover glass and the latter laid on the slide; the bacteria are stained differentially, some parts more intensely than others. (05 Mar 2000) |
| stain | 1. To discolour by the application of foreign matter; to make foul; to spot; as, to stain the hand with dye; armor stained with blood. 2. To colour, as wood, glass, paper, cloth, or the like, by processess affecting, chemically or otherwise, the material itself; to tinge with a colour or colours combining with, or penetrating, the substance; to dye; as, to stain wood with acids, coloured washes, paint rubbed in, etc.; to stain glass. 3. To spot with guilt or infamy; to bring reproach on; to blot; to soil; to tarnish. "Of honor void, Of innocence, of faith, of purity, Our wonted ornaments now soiled and stained." (Milton) 4. To cause to seem inferior or soiled by comparison. "She stains the ripest virgins of her age." (Beau. & Fl) "That did all other beasts in beauty stain." (Spenser) Stained glass, glass coloured or stained by certain metallic pigments fused into its substance, often used for making ornament windows. Synonym: To paint, dye, blot, soil, sully, discolour, disgrace, taint. Paint, Stain, Dye. These denote three different processes; the first mechanical, the other two, chiefly chemical. To paint a thing is so spread a coat of colouring matter over it; to stain or dye a thing is to impart colour to its substance. To stain is said chiefly of solids, as wood, glass, paper; to dye, of fibrous substances, textile fabrics, etc.; the one, commonly, a simple process, as applying a wash; the other more complex, as fixing colours by mordants. Origin: Abbrev. Fr. Distain. Source: Websters Dictionary (01 Mar 1998) |
| Nauta's stain | <technique> A stain for degenerating axons in which they stain with silver and appear as fragmented and swollen fibres. (05 Mar 2000) |
| negative stain | <technique> Stain forming an opaque or coloured background against which the object to be demonstrated appears as a translucent or colourless area; in electron microscopy, an electron opaque material, such as phosphotungstic acid or sodium phosphotungstate, is used to give detail as to surface structure. (05 Mar 2000) |
| Neisser's stain | <technique> A stain for the polar nuclei of the diphtheria bacillus which uses a mixture of methylene blue and crystal violet. (05 Mar 2000) |
| Stirling's modification of Gram's stain | <technique> A stable aniline-crystal violet stain. (05 Mar 2000) |
| neutral stain | <technique> A compound of an acid stain and a basic stain, such as the eosinate of methylene blue, in which the anion and cation each contains a chromophore group. Synonym: salt dye. (05 Mar 2000) |
| Nicolle's stain | <technique> For capsules, stain in a mixture of a saturated solution of gentian violet in alcohol-phenol. (05 Mar 2000) |
| ninhydrin-Schiff stain | <technique> For proteins, proteins are revealed by using ninhydrin or alloxan to produce aldehydes from primary aliphatic amines by oxidative deamination; the aldehydes are shown by reaction with Schiff's reagent. (05 Mar 2000) |
| Nissl's stain | <technique> A method for staining nerve cells with basic fuchsin, a method for staining aggregates of rough endoplasmic reticulum and ribosomes in neuronal cell bodies and dendrites with basic dyes such as cresyl violet (or cresyl echt violet), thionine, toluidin blue O, or methylene blue. (05 Mar 2000) |
| Noble's stain | <technique> A basic fuchsin-orange G staining technique for detection of viral inclusion bodies in fixed tissues. (05 Mar 2000) |
| Sudan stain | <chemical, investigation> Histochemical stains used for lipids. (18 Nov 1997) |
| nuclear stain | <technique> A stain for cell nuclei, usually based on the binding of a basic dye to DNA or nucleohistone. (05 Mar 2000) |
| Da Fano's stain | <technique> A silver stain that produces a blackening of Golgi elements after tissues are fixed in a mixture of nitrate and formalin. (05 Mar 2000) |