PALP: An imaging method for detecting and quantifying polyunsaturated phospholipids via peroxidation

Polyunsaturated phospholipids are essential for multiple cellular functions; however, their uncontrolled peroxidation leads to ferroptosis. Here we describe photochemical activation of membrane lipid peroxidation (PALP), which uses localized laser pulses to induce lipid peroxidation photochemically. While PALP bypasses enzymatic requirements for lipid peroxidation, the resulting BODIPY-C11-based signal is largely correlated with local polyunsaturated phospholipid concentration on membranes. This technique enables non-invasive reporting of lipid unsaturation levels and sensitivity to ferroptosis in live cells.