- 1. A preparation made by extracting a crude drug, precipitating from the solution, and drying. 2. Increasing the amount of solute in a given volume of solution by evaporation of the solvent. 3. The quantity of a substance per unit volume or weight. In renal physiology, symbol U for urinary c., P for plasma c.; in respiratory physiology, symbol C for amount per unit volume in blood, F for fractional c. (mole fraction or volume per volume) in dried gas; subscripts indicate location and chemical species. [L. con-, together, + centrum, center]- Baermann c. preparation that relies on the principle that active nematode larvae will migrate from a fresh fecal specimen through several layers of gauze into tap water, from which the larvae can be recovered by centrifugation.- buffy coat c. centrifugation of whole blood containing anticoagulant to obtain a buffy coat layer containing white blood cells; blood films for staining can be prepared from this layer of cells and examined for the presence of parasites (trypanosomes and intracellular leishmaniae).- critical micelle c. (cmc) the c. at which an amphipathic molecule ( E.G., a phospholipid) will form a micelle.- fecal c. preparation using centrifugation and either flotation or sedimentation methods to separate parasitic elements from fecal debris.- formalin-ether sedimentation c. a sedimentation method to separate parasitic elements from fecal debris through centrifugation and the use of ether to trap debris in a separate layer from the parasites.- formalin-ethyl acetate sedimentation c. a sedimentation method to separate parasitic elements from fecal debris through centrifugation and the use of ethyl acetate (substitute for ether) to trap debris in a separate layer from the parasites.- gravity c. a method of separating parasites from debris through gravity sedimentation of fecal suspensions.- M c. the maximum number of bacterial cells which can be produced in a unit volume of growth medium.- mean corpuscular hemoglobin c. (MCHC) Hgb/Hct; the average hemoglobin c. in a given volume of packed red cells, calculated from the hemoglobin therein and the hematocrit, in erythrocyte indices.- microhematocrit c. the centrifugation of whole, anticoagulated blood, using microhematocrit tubes, to obtain a buffy coat layer containing white blood cells; blood films for staining can be prepared from this layer of cells and examined for the presence of parasites (trypanosomes and intracellular leishmaniae).- minimal alveolar c. the end-alveolar c. of an inhalation anesthetic that prevents somatic response to a painful stimulus in 50% of individuals; an index of relative potency of inhalation anesthetics. SYN: minimal anesthetic c..- minimal inhibitory c. (MIC) the lowest c. of antibiotic sufficient to inhibit bacterial growth when tested in vitro.- zinc sulfate flotation c. a method using saturated zinc sulfate to separate parasitic elements from fecal debris through differences in specific gravity; most parasite cysts, oocysts, spores, eggs, and larvae can be found in the surface film after centrifugation.
* * *1) the act or action of concentrating: asa) a directing of the attention or of the mental faculties toward a single objectb) an increasing of strength (as of a solute or a gas in a mixture) or a purifying by partial or total removal of diluents, solvents, admixed gases, extraneous material, or waste (as by evaporation or diffusion)2) a crude active principle of a vegetable esp. for pharmaceutical use in the form of a powder or resin3) the relative content of a component (as dissolved or dispersed material) of a solution, mixture, or dispersion that may be expressed in percentage by weight or by volume, in parts per million, or in grams per liter
* * *con·cen·tra·tion (kon″sən-traґshən) [L. concentratio] 1. increase in strength by evaporation. 2. the ratio of the mass or volume of a solute to the mass or volume of the solution or solvent. Cf. molarity, molality, normality, and mole fraction.
Medical dictionary. 2011.