Scanning electron microscope

This instrument incorporates cryogenic capabilities and elemental analysis into a robust platform with high-resolution optics. The LEO 1525 scanning electron microscope is built around the Gemini crossover-free SEM column, attaining <2nm resolution at ambient temperature. Even voltages under 500 V are tractable. The system is also equipped with a Gatan Alto 2500 cryogenic system, which includes a turbopumped cryotransfer station, liquid nitrogen-cooled cryo-prep chamber for freeze-etch with Peltier-heated stage, gas-cooled integrated cryostage, and argon-fed sputter coater. The ThermoNoran “System Six” energy-dispersive X-ray spectrometry unit can provide elemental mapping for correlation with the electron image. Due to the poor signal of the in-lens detector, we recommend the in-chamber secondary electron detector be used for all imaging with this unit.

The cryoSEM is easy to learn and competitively priced by the hour. We thank the Center for Advanced Biotechnology and Medicine (CABM) for their assistance in installing this instrument; fees are waived for researchers from that unit. The cryostage is removable and can be replaced with a room-temperature stage in <5 minutes. The policies for this instrument are more liberal than for the cryoFIB/SEM: we do permit large, room-temperature specimens to be introduced through the chamber door of this instrument, bypassing the airlock.