From Big Medical Encyclopedia

ELUTION (Latin elure to wash away, delete; synonym eluating) — one of stages gel filtering or a chromatography consisting in washing away of adsorbate or substances with various hromatografichesky properties the special washing-away solution. AA. the spider is widely used in various fields of biochemistry, medicine and medicobiological where gel filtering (see), a chromatography (see) and an electrophoresis is applied (see).

AA. it is carried out in several ways. In the elementary option through hromatografichesky system constantly pass one solvent; usually as solvents use the diluted saline solutions (see) or buffered solutions (see). The liquid (eluate) quitting the system in case of distribution or gel permeation chromatography usually gathers in the form of separate fractions, in to-rykh hromatografichesk the divided components of the studied mix define by spectral measurements (see Spectroscopy), chemical tests, radioactivity measurement, etc. At preparative unmixing of substances on a column apply step, or periodic, AA. In this case the divided mix is entered into system in one solvent, and then through system pass some other solvents (eluents) having different affinity to formulation components. Advantage of such method is the possibility of exact selection a condition, allowing to receive specific components in small volumes of eluate. So-called gradient elution consists or in change of a ratio between two solvents, or in increase in concentration of one or more components in solvent (e.g., concentration of salt) in the course of chromatographic fractionation. The last option is more widespread during the use of ion-exchange resins or the adsorptive columns (see Adsorption, Sorption).

In case of paper chromatography or in a thin coat the site of a hromatogramma. containing individual substance — one of components of the chromatographed mix, mechanically delete and eluate from it this substance the corresponding eluent.

In case of electrophoretic division in gels of mixes of the loaded substances often use electrophoretic elution. At the same time the electrophoresis is continued up to an exit of components of the studied mix from gel. In biochemical researches (see) and nucleic acids (see) from gels of agarose and polyacrylamide apply many versions of the corresponding devices for E to deproteinization. these connections from substances carriers. Most often the divided biopolymers eluate in a dialysis sack (see Dialysis) or in the camera separated from an anode tank by a dialysis membrane.

Bibliography: See bibliogr. to St. Chromatography , Electrophoresis .

P. L. Ivanov.