ABEL METHOD (L.L. Abell) — one of methods of quantitative definition of the general cholesterol in blood serum.
It is based on ability of a radio extract of cholesterol to give with acetic anhydride and a chamois to - that staining reaction (Libermann's reaction — Burkhardta) which intensity is defined colorimetric.
Technology of definition. In a test tube on 25 ml from 5 ml of spirit caustic heat (6 ml of 33% of solution caustic heat + 94 ml of absolute ethyl alcohol) bring 0,5 ml of serum or a blood plasma, mix and hydrolyze at t ° 37 — 40 ° within 55 min. After cooling add 10 ml of petroleum ether (vigorously stir up), then 5 ml of a distilled water (again stir up).
For direct determination of amount of cholesterol take 4 ml of extract (top coat), evaporate and carry out Libermann's reaction — Burkhardta; kolorimetrirut in 30 min., at the red light filter (620 nanometers); in parallel carry out control reactions with standard solutions of cholesterol (1 ml contains 0,4 mg of cholesterol).
Calculation of amount of cholesterol is carried out on a formula:
where S — the optical density of standard solution of cholesterol, the corresponding 1 mg of cholesterol (receive division of an indicator of optical density of the standard into a kolchestvo of milligrams of the cholesterol used for a kolorimetrirovaniye); V1 — the volume of petroleum ether (10 ml); V2 — the volume of extract of the cholesterol taken for the analysis (in ml); V3 — the volume of the analyzed serum or a blood plasma (in ml).
Normal the content of the general cholesterol in blood fluctuates depending on age within 120 — 250 mg of %.
And. the m is one of modifications of a classical method of definition of the general cholesterol with Libermann's reactant — Burkhardta, directed to acceleration of the analysis. Satisfies the purposes of clinical diagnosis, yielding results comparable among themselves.
See also Blood (research), Holesterin,
Bibliography: Biochemical methods of a research in clinic, under the editorship of A. A. Pokrovsky, page 300, M., 1069; Abell L. L. and. lake of A simplified method for the estimation of total cholesterol in serum and demonstration of its specificity, J. biol. Chem., v. 105, p. 357, 1952.
V. Ya. Maximov.