F211-Microscopy Flashcards
Define Resolution
The ability to see two objects that are close together as seperate objects. To see detail
Define Magnification
The number of times larger the image is compared to the object
What is the magnification of a Light Microscope?
X1500
What is the magnification of a Transmission Electron Microscope (TEM)?
X500,000
What is the magnification of the Scanning Electron Microscope(SEM)?
X100,000
What is the resolution of a Light Microscope?
200nm
What is the resolution of a Transmission Electron Microscope?
0.1nm - 0.4nm
What is the resolution of a Scanning Electron Microscope?
0.1nm - 0.4nm
Define Stains
Coloured chemicals that bind to the specimen.
Some stains bind to specific organelles (iodine stains starch blue/black-methylene stains the nucleus dark blue)
Explain why staining is important
- features become visible and can be seen
- increases contrast
- specific organelles such as nucleus
- allows identification if cell types/organelles
- allows identification of different compounds/molecules
State 3 advantages of a Light Microscope
- can view live specimens as well as dead
- it’s cheap
- does not require a high degree of skill and training to use
State the disadvantages of a Light Microscope
- low resolution of 200nm
- low magnification of x1500
State the advantages of an Electron Microscope
- High resolution of 0.1-0.4 nm
- High magnification of up to x500,000
Stage the disadvantages of an Electron Microscope
- can only view dead specimens
- it’s expensive
- requires a high degree of skill and training to use
What number do you multiply by convert to a smaller unit? & name the units in size order
Multiply by 1000
M
mm
um
nm
