In this tutorial, you will find:
The complete workflow for in situ cryo-electron tomography
How subtomogram averaging within the cell yields native-state structures of macromolecular complexes (e.g., the asymmetric and dilated nuclear pore of algae)
How mapping these structures back into the native cellular environment reveals new molecular interactions that are only accessible by this technique (e.g., the binding of cargo to COPI-coated Golgi membranes and the tethering of proteasomes to the nuclear pore).

Cryo-electron tomography can visualize macromolecular structures in situ, inside the cell. Vitreous frozen cells are first thinned with a focused ion beam and then imaged in three dimensions using a transmission electron microscope. This transformative method has the power to revolutionize our understanding of cell biology, revealing native cellular architecture with molecular clarity.