Main Page | See live article | Alphabetical index Stain has several possible meanings: A stain can be an unwanted localized discoloration, often in fabrics or textiles. Wood stain is a type of penetrative dye used to create a wanted color change in wood. Stains are used in biology and medicine to highlight tissues or cells. In vivo staining is used within living organisms In vitro straining is used on tissue or cells that are no longer within a living organism. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.