Subcellular chemical mapping using correlated cryogenic electron and mass spectrometry imaging (nature.com)

• Cryo-EM-FIB-SIMS provides subcellular chemical imaging
• BPAF is sequestered in phase-separated aggregates within bacterial storage granules
• Workflow compatible with cryo-light microscopy and eukaryotic lamellae

"A novel workflow combining cryo-EM with focused ion beam secondary ion mass spectrometry (FIB-SIMS) maps chemical signatures in biological specimens at subcellular resolution. Demonstrated on bacteria and eukaryotic cells, the method was applied to study bisphenol-AF (BPAF) uptake by environmental bacteria, revealing storage in cytosolic phase-separated aggregates that cannot be removed despite efflux pump upregulation."