Question

Osmium tetroxide is used in

• A. Light microscopy
• B. Electron microscopy
• C. Phase contrast microscopy
• D. X-ray diffraction microscopy

Answer 1

The correct option is B Electron microscopy

Osmium tetroxide is useful in electron microscopy. It is a widely used staining agent in transmission electron microscopy (TEM) to provide contrast to the image. As a lipid stain, it is also useful in scanning electron microscope (SEM). It embeds a heavy metal directly into cell membranes, creating a high electron scattering rate without the need for coating the membrane with a layer of metal, which can obscure details of the cell membrane.