Research laboratory

Viewing instruments

Microscopy, to see the invisible

Thanks to the optical microscope, it is possible to observe things invisible to the naked eye – for example, microorganisms that are 100 to 1000 times smaller than a millimeter, such as animal, vegetal, or bacterial cells. The electron microscope allows us to see even smaller microorganisms, such as viruses, for example, that we cannot see with an optical microscope. Today, it is even possible to observe macromolecules.

Discover different types of microscopes manufactured to respond to the researchers' many needs.

Optical microscopeZoomZoom
© Armand-Frappier Museum

Optical microscope

The microscope is an optical instrument that gives an enlarged image of microorganisms spread on a glass slide deposited on a rectangular tray or stage. Thanks to the three magnifying objective lenses placed right above the stage, and to a light source illuminating from above, the observer can see the microorganisms by placing his eye on the eyepiece. The objectives and eyepiece are composed of glass magnifying lenses. The Bausch and Lomb model presented in the photograph requires the use of an external light source, a lamp with its beam directed on the mirror that has an adjustable angle. It was used at the Institut de Microbiologie et d'Hygiène de l'Université de Montréal.

Optical microscopeZoomZoom
© Armand-Frappier Museum

Optical microscope

In this model, the light source is integrated into the instrument.

Inverted microscopeZoomZoom
© Armand-Frappier Museum

Inverted microscope

The peculiarity of this microscope is that the position of its components is inverted compared to conventional microscopes. The light bulb that illuminates the specimen is placed in the cylindrical part at the top and the objectives are placed under the specimen on the circular stage. Such a system is used to observe cells organized in tissue. For example, skin cells can develop by adhering to the wall in a flask filled with nutrients. Using this microscope, we can observe the growth of the tissue through the wall of the flask. This model is connected to a transducer that supplies current to the electric light bulb.

PhotomicrographyZoomZoom
© Armand-Frappier Museum

Photomicrography

This microscope, in use since 1967 at the Institut de Microbiologie et d'Hygiène, is equipped with a device that can photograph directly the result of the microscopic observation. The upper, gray, part of the microscope includes a cassette to install the film. This practice, known as photomicrography, goes back to the invention of the photographic process and was used this way until the 1990s. Since then, scientists have preferred to use cameras and digital technology to reproduce their microscopic observations.

MicrocinematographyZoomZoom
© Armand-Frappier Museum

Microcinematography

The Nikon inverted microscope that we see in the photograph is equipped with a 16 mm movie camera fixed to the right of the base. It would also be possible to install a still photography camera. The microscope, equipped in this manner, was used to do photomicrography and microcinematography of the biological material observed under the microscope. The resulting film could be projected and used for teaching or to review certain phenomena in fast or slow motion to analyze them from a different perspective. Use of cinematography in the biological sciences goes back to the 1900s. In 1908, the French company Pathé hired Dr Jean Comandon, a pioneer of scientific microcinema. Use of 16mm film became common practice starting in 1945.

Electron microscopeZoomZoom
© Armand-Frappier Museum

Electron microscope

The electron microscope uses a beam of electrons controlled by a system of magnetic fields.

With the electron microscope belonging to the INRS-Institut Armand-Frappier, it is possible to obtain magnifications up to 600,000 X on the main screen but with a television camera, a magnification of 12,000,000 X can be reached. Furthermore, by increasing the height of the column, higher magnifications can be attained. With supermicroscopes, one can even see macromolecules.

Depending on the focal lengths chosen, one can obtain magnifications between 1,000 and 600,000 X and even more with high yield microscopes. The image can be further magnified (8-10 X) with binoculars or a television camera (20 X).