Cellular Fatty Acid Analysis in Macrophage Using Stable Isotope Labeling

Fatty acids (FAs) are essential for building complex lipids, posttranslational modifications, and energetics. FAs can be imported from extracellular sources or synthesized by cells. The analysis of fatty acid methyl esters (FAMEs) by gas chromatography-mass spectrometry (GC-MS) allows for the quantitative analysis of long-chain and very-long-chain fatty acid content of cells. When coupled with isotopic labeling, this approach can elucidate the synthetic pathways being engaged by the cells, and the relative contribution of synthesis and import to maintain lipid content. Here, we describe a method for total cellular fatty acid analysis in macrophages.