Transmission electron microscopy (TEM)

The IRDQ offers an extensive range of transmission electron microscopes (TEM) which, combined with the expertise developed by highly qualified professionals, can provide a solution to the most demanding problems: analysis of small metallic particles (catalysts), self-assembled peptide arrays, 3D reconstruction of biological structures…

A sample analyzed by TEM must first be prepared in thin strips approximately 200 nm thick; the resulting small volume allows the sample’s analysis in transmission, including chemical and crystallographic analyses. The thin strips are prepared by dedicated equipment such as a focused ion beam, ultramicrotomes and cryogenic units (for the subsequent study of biological specimens).

Types of analysis

The TEM’s high space resolution makes it possible to characterize stereological parameters such as the size, shape or spatial distribution of structures. Chemical analyses can be conducted by energy dispersion X-ray spectroscopy (EDS) as well as electron energy loss spectroscopy (EELS). The latter can also yield information on chemical links between atoms and allows thickness measurement.

The JSM 2100-F transmission electron microscope makes such measurements possible. The electron beam, with a minimum diameter of just 0.2 nm lends itself to imaging with a resolution of 0.14 nm. This makes the observation of atoms in crystalline samples possible, and permits the study of new materials developed on an atomic scale.

Biological analyses

To preserve the integrity of biological samples, cryogenic units must be used for both the preparation of samples and electron microscopy. Three cryogenic electron microscopes are available; the most recent acquisition, the Titan Krios 300 kV Cryo FE STEM by FEI, is unique in Canada. It features a Gatan Imaging Filter (GIF) and a CCD 16 megapixel camera allowing the 3D reconstruction of images with near-atomic resolution, making the Krios unique in the fields of medicine and biology.