Home > Microscopy > Scanning Electron Microscopy
The CMIF is home to an FEI NOVA nanoSEM scanning electron microscope equipped with secondary and low-vacuum detectors. This microscope is ideal for most biological and material specimens, as it is fully digital,and powered by a field-emission gun (FEG) electron source. The microscope is mouse driven and is well suited to low, intermediate, and high-resolution work. For ultra-high resolution the instrument is equipped with an additional through-the-lens detection system.
Specimen preparation equipment for the SEM includes a Cressington critical point drier and a Pelco Model 3 sputter coater. Standard protocol for the preparation of biological specimens for SEM includes a fixation procedure, dehydration, and critical point drying from ethanol. This procedure replaces the ethanol with liquid carbon dioxide under pressure, and upon raising the temperature above the critical point for carbon dioxide, the liquid goes directly to a gas phase without causing any of the shrinkage which would accompany air drying. After mounting the dried specimens on stubs, they are sputter-coated with a heavy metal, generally platinum, gold or gold-palladium, to convey electrical conductivity and observed in the SEM.