Improved determination of very-long-chain fatty acids in plasma and cultured skin fibroblasts: applications to the diagnosis of peroxisomal disorders.

Current techniques for the determination of very-long-chain fatty acids from biological samples require laborious procedures including solvent extraction of lipids, purification, hydrolysis, derivatization, purification of derivatized fatty acids by thin-layer chromatography and finally gas chromatographic analysis. A comparison was made between such a procedure based on solvent extraction and a method based on a recently developed direct one-step transesterification reaction. The latter method proved to be much faster and led to higher recoveries of all individual very-long-chain fatty acids from both plasma and skin fibroblasts. The assay proved to be very convenient in the diagnosis of genetically determined disorders in which very-long-chain fatty acids accumulate in tissues and body fluids. Because of its simplicity and speed and because it can be performed with as little as 100 microliters of plasma, the method can be recommended as a valuable screening procedure for peroxisomal disorders.