3.3 microscopes Flashcards
What is the function of the light microscope
Light is focused using glass lenses and light is able to pass through the specimen
What is the resolution of the light microscop
Low due to wavelength of light (2um)
What is the magnification of the light microscope
Low
What are the advantages of the light microscopes
Easy to use
cheap
‘True colour’ (sometimes requires staining)
Can use live specimen
What are the limitations of the light microscopes
Specimens are thing therefore may not be representative
WHat is the function of a scanning electron
Directs a beam of e- at a specimen; image created based on the e- that are reflected. Focused using electromagnets
WHat is the resolution and magnification of the scanning electron microscopes
Resolution: High (1nm)
Magnification: High (200,000 x)
What are the advantages of the scanning electron microscopes
Provide detailed images of surface structure, ‘3D image’
What are the limitations of the scanning electron microscope
Expensive,
extensive training required
Samples must be dead (vacuum, staining)
Black and white / false colour
What is the function of the transmission electron miscroscope
Directs a beam of e- at a specimen; image created based on the e- that are absorbed
What are the magnification and resolution of the transmission electron microscope
Magnification: High (1nm)
Resolution: High (500,000 x)
What are the advantages of the transmission electron microscope
Provides a detailed image of interior structures
What are the limitations of the transmission electron microscope
Expensive
extensive training required
Samples must be dead
