When I first looked at this micrograph i thought perhaps the electron density under the mitochondrion (here above two desmosomes, tangentially cut and off center, was a bundle of intermediate filaments. That would be interesting since i don’t know if filament bundles likely composed of keratins 5 and 14, could make this tethering bridge between desmoplakin –part of the desmosome in complex with two remote points on the mitochonrdion.

Turns out that It looks more like a little invagination along part of the plasmalemma of the mitcohondrion, probably representing outer mitochondrial membrane. Red dit=ribosome@27nm, blue curley bracket=bridge, red lines, intermediate filaments bottom red lines, underscoring position of thedesmosomes.