The FEI Tecnai Spirit G2 is a 120kV transmission electron microscope (TEM). It was purchased with the support of Northwestern University Office for Research, and is housed in the EM suite (Searle 2-575) of the Cell Imaging Facility.

The Tecnai system is an important addition to the TEM capability of the Cell Imaging Facility. In addition to its greatly improved capability to generate high contrast and to image much thicker sample, the system is capable of performing 3D TEM tomography. This is a tomography technique for obtaining detailed 3D structures of subcellular macromolecular object. Using a titltable sample holder, the sample will be tilted at varying degree, usually at 1 degree increment during the 3D image acquisition process. An electron beam is therefore passed through the sample also at incremetal degrees of rotation around the center of the specimen. The information is then collected and used to reconstruct a three representation image of the target. Current resolutions of 3D tomography are in the 5-20 nm range, suitable for examining supra-molecular multi-protein structures, although not the secondary and tertiary structure of an individual protein or polypeptide.

As shown in the movie below, we have combined our platinum replica TEM technique with 3D tomography to examine the three dimensional architecture of the actin cytoskeletal network in endothelial cells.

Please contact Mr. Lennell Reynolds (312-503-4445) to schedule for training and consultation to use the FEI Tecnai TEM system.