Contamination Buildup on cryo EM grids

Contamination Buildup on cryo EM grids

Aqueous contaminant deposits on cold grids in the electron microscope over time. The red line in this time-dependency plot is the average of the 9 measurements shown as connected scattered points. How to minimize contamination? 1) Position the aniticontaminator properly; 2) do not leave photographic film in the microscope if not needed; 3) wait for 1hr or more before exposing the cryo grid to the freshly inserted film magzine since the insertion creates a jump in contamination rate. The best protection gives contamination rate of ~1 angstrum/hr.

Anchi Cheng – NRAMM