CONCURRENT QUANTIFICATION OF CELLULAR CHOLESTEROL, CHOLESTERYL ESTERSAND TRIGLYCERIDES IN SMALL BIOLOGICAL SAMPLES - REEVALUATION OF THIN-LAYER CHROMATOGRAPHY USING LASER DENSITOMETRY

Absolute specificity and high accuracy is required for the quantitatio n of cholesterol, cholesteryl esters and triglycerides in small biolog ical samples, particularly in a limited number of cells. Both can be a chieved through thin-layer chromatography and molybdatophosphoric acid staining, while the shortcomings of traditional spot detection are ov ercome by laser densitometry. The major advantage of the proposed tech nique is the concurrent assay of nanogram quantities of cholesterol, c holesteryl esters and triglycerides. Our assay is at least ten-fold mo re sensitive than common thin-layer chromatography-based techniques an d at least four-fold more sensitive than common enzymatic methods. The present low-cost assay is highly reproducible and may be particularly suitable for the routine lipid analysis of a 10% aliquot of relativel y small tissue and cell samples, equivalent, for instance, to greater than or equal to 10(4) human monocytes.