Titer(redirected from agglutination titer)
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(in analytical chemistry), the concentration of a solution expressed as the amount (in grams) of a substance dissolved in 1 milliliter (ml) of solution or as the amount of any substance that reacts with 1 ml of the given solution. Accordingly, a distinction is made between the titer for a dissolved substance (for example, the titer of the solution of hydrochloric acid, THCI) and the titer for a substance to be determined (for example, the titer of the solution of hydrochloric acid for sodium hydroxide, THCI/NaOH). The titer is calculated from the formula T = P/V, where T is the titer of the solution in g/ml, P is the weight of the batch in g, and V is the volume of the measuring flask in ml. Solutions with a known titer, called standard solutions, are used in titrimetric analysis.
in immunochemical analysis, the maximum or optimum dilution of antigens, antibodies, or complement at which a positive reaction between antigens and antibodies can be recorded or the reaction of one or both components can be registered against a standard. In some cases, such as complement fixation, the maximum antigen concentration at which sensitized erythrocytes can still be lysed is taken as the antigen titer. Determination of the titer is useful in making a quick estimate of the activity of immune serums.
Three kinds of titration are used in immunochemical analysis. In one method, pipettes are used to add different amounts of the material being titrated to identical volumes of the solvent or for successive transfer of a mixture of the material and solvent to test tubes containing an identical quantity of solvent; in the latter case, equal volumes of the material, solvent, and mixture to be transferred are usually taken, which produces twofold dilutions. The second method is similar, except that capillary tubes are used and the volumes are measured from the number of drops. Glass loops capable of holding strictly standard volumes of liquid are used in automatic titration.
N. A. DORFMAN
(titre), in the textile industry, a number used to rate the thickness of fibers and yarns (chiefly silk). The titer is expressed as the product of the cross-sectional area of a fiber or yarn and the density of its material (or as the ratio of the weight of a fiber or yarn to the length). The titer came into use in the 18th century. A unit known as a legal titer has been used since 1900; it is numerically equivalent to the weight in grams of a yarn 9 km in length. In the USSR the tex replaced the titer in 1956.