A 200 kV electron microscope with Schottky field emitter and a helium-cooled superconducting objective lens

Abstract Electron microscopy of biological structural research has made significant advances. These advances were the stimulus to develop an electron microscope containing most of the desirable features and methods for high resolution cryo-electron microscopy. The new instrument is a modified commercial Philips CM 20 FEG electron microscope equipped with a helium-cooled cryoobjective from Siemens. This paper presents the essential features and research possibilities of this new microscope named “SOPHIE” (acronym for S uperconducting O bjective in a PHI -lips E lectron microscope).