Metal-induced energy transfer (MIET) imaging is an easy-to-implement
super-resolution modality that achieves nanometer resolution along
the optical axis of a microscope. Although its capability in numerous
biological and biophysical studies has been demonstrated, its implementation
for live-cell imaging with fluorescent proteins is still lacking.
Here, we present its applicability and capabilities for live-cell
imaging with fluorescent proteins in diverse cell types (adult human
stem cells, human osteo-sarcoma cells, andDictyostelium discoideumcells), and with various fluorescent proteins (GFP, mScarlet, RFP,
YPet). We show that MIET imaging achieves nanometer axial mapping
of living cellular and subcellular components across multiple time
scales, from a few milliseconds to hours, with negligible phototoxic
effects.