Lipid and lipoarabinomannan isolation and characterization.

Mycobacteria are microorganisms that contain a very high content of structurally diverse lipids, some of them being biologically active substances. As such the lipid composition is commonly used to characterize mycobacterial strains at the species and type-species level. This chapter describes the methods that allow the purification of the most commonly isolated biologically active lipids and those used for analyzing extractable lipids and their constituents, cell wall-linked mycolic acids and lipoarabinomannan (LAM). The latter involve simple chromatographic and analytical techniques, such as thin-layer chromatography and gas chromatography coupled to mass spectrometry.