Rapid analysis of cellular lipids without extraction.

A method is described where cell suspension obtained by scraping of monolayers was directly applied on silica gel plates. Extraction and separation of different lipid classes were simultaneously obtained during chromatography. In the range of validity of the method (no more than 80 micrograms of cellular protein tested for neutral lipids and 30 micrograms for phospholipids), this technique allows rapid lipid analysis of small samples of cultured cells, bypassing all the time- and solvent-consuming extraction and evaporation steps. The method appears to be also suitable for measurement of enzymes of lipid metabolism such as acyl coenzyme A-cholesterol-acyltransferase.