Fig. 1

Schematic visualization of a MALDI measurement analyzing QS events in a bacterial biofilm. Middle: A laser impacts the bacterial biofilm surface. The laser ionizes the QS molecules, and the ions are analyzed by the mass spectrometer. Right: The mass spectra of single coordinates are combined into ion images, showing MALDI-MSI images of different lipids in S. aureus biofilm grown for four days. These images were generated in positive mode on a Rapiflex (Bruker Daltonics) at 20 μm of lateral resolution using sublimed 2,5-Dihydroxybenzoic acid as a MALDI matrix. Bottom left: a simplified visualization of a QS event. This figure is created with BioRender.com