2.1.1: Electron (TEM And SEM) And Laser Scanning Confocal Microscopes

Question 1

What is an Electron Microscope (EM)?

Answer 1

A device that uses a beam of electrons to create high-resolution images of small organelles and internal structures.

An image is created using an electromagnet to focus the beam of negatively charged electrons.

Question 2

Why must samples for an Electron Microscope be in a vacuum?

Answer 2

Electrons are absorbed by air, which prevents proper imaging.

This is why only non-living specimens can be examined.

Question 3

What type of image do Electron Microscopes produce?

Answer 3

Black and white images, as samples must be stained.

Question 4

What is a Transmission Electron Microscope (TEM)?

Answer 4

A type of electron microscope that produces 2D images by passing a beam of electrons through extremely thin, stained specimens.

Some parts of the specimen absorb electrons, making them appear darker.

Question 5

What is a Scanning Electron Microscope (SEM)?

Answer 5

A microscope that beams electrons onto the surface of specimens, producing 3D images based on electron scattering.

The specimens do not need to be thin.

Question 6

What is a Laser Scanning Confocal Microscope?

Answer 6

A type of fluorescent microscope that uses high light intensity to illuminate stained specimens, allowing for high-resolution optical imaging and depth selectivity.

It creates 2D or 3D images by scanning the specimen point-by-point with a focused laser beam.