Study of a recently proposed iron-sulfuric acid cholesterol method

Abstract

Precision and specificity of the Babson iron-sulfuric acid cholesterol procedure can be improved by carrying out the reaction isothermally and by extracting cholesterol from sera in the presence of the silver salt of an ion exchange resin. The proposed modification is free of interference from bilirubin, tryptophan, bromide, hemoglobin, and polyunsaturated fatty acid residues. Esters are underestimated; therefore a pooled serum, whose cholesterol content is independently determined by a rigorous assay procedure, is recommended for daily standardization.