| Gram's stain | <microbiology, technique> A method for differential staining of bacteria; smears are fixed by flaming, stained in a solution of crystal violet, treated with iodine solution, rinsed, decolorised, and then counterstained with safranin O. Gram-positive organisms stain purple black and Gram-negative organisms stain pink; useful in bacterial taxonomy and identification, and also in indicating fundamental differences in cell wall structure. (05 Mar 2000) |
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| Gram stain | <microbiology, procedure> A method of staining bacteria using a violet stain. The gram staining characteristics (denoted as positive or negative) can assist in the identification of the offending bacteria. A heat fixed bacterial smear is stained with crystal violet (methyl violet), treated with 3% iodine/potassium iodide solution, washed with alcohol and counterstained. The method differentiates bacteria into two main classes, gram-positive and gram-negative. Certain bacteria, notably mycobacteria, that have walls with high lipid content show acid-fast staining the stain resists decolouration in strong acid. (27 Sep 1997) |
| Weigert-Gram stain | <technique> A stain for bacteria in tissues in which sections are stained in alum-haematoxylin, then in eosin, aniline methyl violet, and Lugol's solution. (05 Mar 2000) |
| half-a-gram stain | <technique> A lab technique used to detect the presence of members from the bacterial family Legionellaceae in samples of sputum. (09 Oct 1997) |
| Stirling's modification of Gram's stain | <technique> A stable aniline-crystal violet stain. (05 Mar 2000) |
| centimeter-gram-second system | The scientific system of expressing the fundamental physical units of length, mass, and time, and those units derived from them, in centimeters, grams, and seconds; currently being replaced by the International System of Units based on the meter, kilogram, and second. (05 Mar 2000) |
| centimeter-gram-second unit | <unit> An absolute unit of the centimeter-gram-second system. (05 Mar 2000) |
| gram | A gram is the unit of measurement used to measure mass in the metric system. It is equal to the mass of one millilitre (one thousandth of a litre) of water at the temperature where water has the highest density (4 degrees C). (09 Oct 1997) |
| gram-atomic weight | Atomic weight expressed in grams. Compare: mole. (05 Mar 2000) |
| gram calorie | The quantity of energy required to raise the temperature of 1 g of water 1캜, or from 14.5캜 to 15.5캜 in the case of normal or standard calorie. Synonym: gram calorie. (05 Mar 2000) |
| gram-centimeter | The energy exerted, or work done, when a mass of 1 g is raised a height of 1 cm; equal to 9.807 × 10-5 joules or newton-meters. (05 Mar 2000) |
| gram equivalent | The weight in grams of an element that combines with or replaces 1 gram of hydrogen, the atomic or molecular weight in grams of an atom or group of atoms involved in a chemical reaction divided by the number of electrons donated, taken up, or shared by the atom or group of atoms in the course of that reaction, the weight of a substance contained in 1 liter of 1 normal solution; a variant of. Synonym: combining weight, equivalent weight. (05 Mar 2000) |
| Gram, Hans | <person> Danish bacteriologist, 1853-1938. See: Gram's iodine, Gram's stain, Weigert-Gram stain. (05 Mar 2000) |
| gram-ion | <chemistry> The weight in grams of an ion that is equal to the sum of the atomic weights of the atoms making up the ion. (05 Mar 2000) |
| gram-meter | <unit> A unit of energy equal to 100 gram-centimeters. (05 Mar 2000) |