…a staining technique for the preliminary identification of bacteria, in which a violet dye is applied, followed by a decolorizing agent and then a red dye. The cell walls of certain bacteria (denoted Gram-positive) retain the first dye and appear violet, while those that lose it (denoted Gram-negative) appear red…
…a kind of large, deep red birthmark, a persistent haemangioma or naevus, typically on the face…
…frote suavemente la mancha con un trapo húmedo…
