Theory 27/Cryo-Electron Microscopy

Resolution Is a Dose Ratio

The claim

Cryo-EM resolution is set by the ratio of electron dose to beam-induced motion rather than by dose alone, so more dose can reduce resolution on a moving specimen.

01The mechanism

Signal improves with dose while damage and motion blur grow; the ratio sets the optimal exposure.

02Predictions

P1Resolution should peak at an intermediate dose.
P2Motion correction should shift the optimum.

03Refutation

Resolution increasing monotonically with dose would remove the motion term.