Evaporated carbon stabilizes thin, frozen-hydrated specimens

A relatively simple modification has been designed and built for a commercial freeze-fracture machine which makes it possible to evaporate carbon onto frozen-hydrated specimens after the specimen grid has been mounted into a side-entry electron microscope cryo-holder. The evaporated carbon film greatly improves the stability of self-supported, vitreous ice films during exposure to the electron beam. Specimen charging is also greatly reduced. As a consequence, the image resolution attainable with carbon-coated, vitreous ice specimens appears to be limited only by the mechanical stability of the cryostage itself. (13 References)