Description

The transmission electron microscope (TEM) uses electrons as the source of illumination.  The image is formed by electrons that pass through the sample.  Thus, a TEM is useful for investigating the internal structures of various materials such as cells of plant and animal tissues, bacteria, viruses, and nanomaterials of all kinds.  The addition of X-ray microanalysis to the microscope enables the determination of the elemental composition of the samples observed.  In addition, specific proteins can be localized in samples using colloidal gold labeled antibodies.  Samples for the TEM must be very thin or made thin by sectioning with an ultramicrotome.

 

Equipment and Specifications

The OSU Microscopy Facility has a JEOL JEM-2100 Scanning Transmission Electron Microscope (STEM) with Bruker Quantax 200 energy-dispersive X-ray microanalysis (EDS) system. It has the following specifications.

• resolution of 0.14nm (image lattice)
• accelerating voltages up to 200KV
• equipped with a LaB6 gun
• scanning image observation device (ASID) for scanning transmission images
• bottom mounted High Mag 4megapixel digital camera system

Bruker energy-dispersive X-ray microanalysis system with fully quantitative analysis software package that includes X-ray mapping capabilities; Bruker QUANTAX EDS features the XFlash^®6 detector series with active areas from 10 to 100 mm².(http://www.bruker.com/).

 

Applications

The Transmission Electron Microscope is being used to identify viruses in animal diseases and determine how they move and survive in the infected animal, to study the mechanism by which plant viruses infect tobacco plants, to determine the toxicity of nanoparticles and to define the size, shape and composition of nanowires and to image secretory proteins in several bacterial species.