Cells - Microscopes Flashcards
Optical, SEM's & TEM's
How does an optical microscope work?
By using light to form an image.
What is the max resolution of an optical microscope?
0.2 micrometres
What are the three types of electron microscope?
Transmission electron microscope (TEM)
Scanning electron microscope (SEM)
Reflection electron microscope (REM)
How do SEM’s work?
They send a beam of electrons across the specimen.
What is a disadvantage of TEM’s?
Only can be used on thin specimen.
Only used on non-living specimens.
What is a disadvantage of SEM’s?
Lower resolutions.
How do TEM’s work?
Transmits electrons through specimen.
What is an advantage of TEM’s?
High resolution.
What is an advantage of SEM’s?
Can be used on thick specimen.
Creates 3D images.
What is an advantage of Electron microscopes?
High resolution & magnification.
What is a disadvantage of Electron microscopes?
Expensive, training required to use them, only used on dead specimen, large and not portable.
What is an advantage of light microscopes?
Affordable, easy use, portable and live samples can be used.
What is a disadvantage of light microscopes?
Poor resolution at high magnification.
