Method and reagent for determining total cholesterol in blood serum

Claim 1

A method according to claim 1 wherein said color-developing reagent is a mixture of ferrous sulfate and sulfuric acid.

Claim 9

A method for the quantitative colorimetric determination of total cholesterol in a cell-free body fluid sample comprising: a. intimately admixing said sample with about 200 parts by weight based on the weight of said sample of an acetic acid solution containing about 0.055 percent, by weight, of a mixed salt comprising ferric acetate and uranium acetate, the weight ratio of ferric acetate to uranium acetate being from about 4:1 to about 4.5:1, b. allowing the mixture to stand for from about 5 to about 10 min. whereby the total cholesterol in said sample is solubilized and the chromogens contained in said sample which interfere with said colorimetric determination are precipitated, c. centrifuging said mixture to segregate said precipitate from a liquid phase containing solubilized total cholesterol, d. separating 3 ml. of said liquid phase from said segregated mixture, e. adding to said separated liquid phase 2 ml. of a reagent comprising a mixture of sulfuric acid and ferrous sulfate wherein the ratio of ferrous sulfate to sulfuric acid, by weight, is about 1:18,000 whereby a purple color of reaction is developed, f. analyzing said liquid phase colorimetrically by measuring the optical density thereof, and g. determining the total cholesterol content of said sample by comparing said measured optical density with that of a standard.