Optimizing Cryo-FIB Lamellas for sub-5 Angstrom in situ Structural Biology

We here present a method based on metallic platinum sputtering that can substantially enhance the quality of subtomogram averages from lamellas and thereby reduce the number of particles needed for high-resolution subtomogram averaging. We provide evidence for the physical background of this improvement and demonstrate its usefulness by producing sub-5 Angstrom ribosome averages from yeast. ### Competing Interest Statement V.V., M.Z., R.K. and A.K. are employees of Thermo Fisher Scientific. The other authors declare no competing interests.