Spectrophotometric determination of dolichol and dolichyl derivatives using the Chugaev color reaction

A simple colorimetric method for the assay of microamounts of dolichol is described. It is based essentially on the Chugaev color reaction. The procedure allows the rapid (1 h after purification of the sample, less than half a day for the whole procedure) and reliable (% SE less than or equal to 5%) determination of dolichol and dolichyl derivatives in the microgram range. Color production is linear within the concentration range 2 to 20 micrograms dolichol. With biological samples, prior to colorimetric assay, dolichol and dolichyl derivatives are isolated by solvent extraction and TLC. Recoveries are monitored by isotope dilution analysis. The method has been used for the analysis of dolichol and dolichyl ester levels in bovine thyroid tissue. The procedure can also be applied for the analysis of other isoprenoids.