Module 2: Microscopy Flashcards
What magnification does a light microscope have?
x1500
What resolution does a light microscope have?
0.2 micrometres
Advantage of using a light microscope?
Can visualise living cells and can watch behaviours in real time
Disadvantage of using a light microscope?
Low resolution
Cant see smaller organelles like ribosomes or lysosomes
How does a laser scanning confocal microscope work?
Use laser beams of light to scan a specimen which will be labelled with a fluorescent tag
This is focused through a pinhole onto a detector
Detector transmits the 3D image onto a computer
Advantage of a laser scanning confocal microscope?
Produce clearer images than normal light microscopes
Used to look at different depths
Magnification of a transmission electron microscope?
x1,000,000
Resolution of a transmission electron microscope?
0.0002 micrometres
How does a transmission electron microscope work?
Uses electromagnets to focus a beam of electrons at a sample
Advantage of a transmission electron microscope?
Electrons have a much shorter wavelength than light so produces a more detailed image
Disadvantage of a transmission electron microscope?
Sample needs to be fixed and placed in a vacuum so live cells cannot be used
Magnification of a scanning electron microscope?
x500,000
Resolution of a scanning electron microscope?
0.002 micrometres
How does a scanning electron microscope work?
Emit a beam of electrons towards a sample, knocking electrons off it and builds an image
Disadvantage of a scanning electron microscope?
Dead specimens
Big and expensive
