Live-cell STED microscopy of mitochondrial cristae

Mitochondria are highly dynamic organelles that exhibit a complex inner architecture. They exhibit a smooth outer membrane and a highly convoluted inner membrane that forms invaginations called cristae. Imaging cristae in living cells poses a formidable challenge for light microscopy. Relying on a cell line stably expressing the mitochondrial protein Cox8A fused to the SNAP-tag and using STED ( st imulated e mission d epletion) super-resolution microscopy, we demonstrate the visualization of cristae dynamics in cultivated human cells.