Whole-Cell Lipidomics with Matrix-assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS)

The lipids of biological organisms play an important role in their structural and physiological functions, such as energy storage, regulation of membrane permeability and signaling of molecules. The change of lipid composition can reflect the physiological state of an organism at a given time. As a result, lipid analysis, in particular lipid profiling, can be an effective approach to monitor the toxicity of environmental and biological factors on the organism. We are investigating direct, label-free analysis platforms for the identification of lipids directly on intact cells without any chemical treatment or purification, using a gold-microchip in combination with MALDI-TOF mass spectrometry. The gold microchip enables enhanced metal fluorescence, which produces a direct visual effect and thus locates the fixed cells. Our ongoing work includes bacterial and algae analysis, but this platform can potentially be applied further to a broad spectrum of lipid analyses such as cancer cells and exosomes.