A simplified procedure for the concentration,desalting, and thin-layer chromatography of mevalonic acid from reaction mixtures used to assay 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity

A procedure has been described for the quantitative isolation of ¹⁴C]-mevalonic acid from reaction mixtures used for the assay of 3-hydroxy-3-methylglutaryl-coenzyme A reductase. It consists of absorbing the reaction mixtures on Whatman No. 4 filter-paper supports and concentrating the radioactive substrate and the product within a 2-mm² area of the paper by two-dimensional elution with nonpolar solvents. This procedure simultaneously results in desalting of the reaction mixture, thus facilitating an excellent thin-layer chromatographic separation of mevalonolactone uncontaminated by the radioactive substrate. Among other advantages of the method are (a) quantitative extraction of mevalonolactone, thus avoiding the necessity of using an internal standard; (b) possibility of simultaneous processing of a large number of samples with the elution being carried out overnight without frequent supervision; (c) simplicity of the technical operations involved; and (d) inexpensiveness of the materials needed for analysis.