Electromicroscopy

Electron microscopy (EM) is a powerful technique used to study the internal structure or surface morphology of materials and biological objects. With EM, details of a few nanometres can be observed. uu77's General Instrumentation facility houses two transmission electron microscopes (TEM) and all common EM auxiliary equipment. Users can also rely on the knowledge of an experienced EM technician.

The instruments are primarily intended for researchers and students of the Faculty of Science or persons who have a permanent collaboration with Science departments. However, companies and other organisations from outside the Faculty of Science can also use the facilities under certain conditions and for a fee.

The equipment is managed by Hetty Manenschijn. Hetty provides instructions on how to use these EM instruments, as well as advice on the choice of techniques. Those interested should contact her in a timely manner.

The transmission electron microscope

Transmission electron microscopes (TEM) are powerful instruments used to study the fine structure of materials on a nanoscale. These microscopes use a beam of electrons instead of light to form images, enabling them to achieve a much higher resolution than traditional light microscopes.

How does it work?

For a TEM study, a thin sample is prepared on a special TEM grid (sample holder). In the TEM, the sample is irradiated with a beam of electrons. As the electrons travel through the material, they are scattered by the atoms in the material. The degree of scattering depends on the density and type of atoms in the material. Electrons that are not scattered pass through the material and form an image on a detector.

Applications

TEM is widely used in various scientific and industrial fields, including materials science, biology and nanotechnology. In biology, for example, TEM is used to study the ultrastructure of cells and viruses. In materials science, TEM helps analyse the crystal structure and defects in materials.

Advantages and limitations

One of the greatest advantages of TEM is its high resolution, which makes it possible to see structures at the atomic level. This makes TEM indispensable for research that requires detailed information about the internal structure of materials. However, preparing samples for TEM is complex and time-consuming, and often requires special treatments such as adding heavy metals to increase contrast.

TEMs available at General Instrumentation

The GI has two transmission electron microscopes. The is intended for routine observations and is usually used at 120 kV. It is relatively easy to use, and new users can work with this device fairly independently after half a day of training.

We also have a . This TEM is more powerful and versatile, and is usually operated at 200 kV. This TEM is also suitable for cryo-TEM, (cryo)tomography and STEM.

TEM peripherals

The General Instrumentation department has its own laboratory filled with equipment needed to prepare TEM samples. The following techniques and equipment are available:

Cryo-holder, dock and pumping station
High pressure freezing – HPM100, EMPACT
Plunge freezing – Vitrobot
Freeze substitution – 3 AFS machines
Embedding cells in resin
Cutting sections – various (cryo)microtomes and a vibrating microtome
Glow discharging, sputter coating, carbon coating – CCU-010