2.1. 1-3 Microscopes Flashcards
What is an electron micrograph?
photograph of an image seen using an electron microscope
Define magnification
the number of times large an image appears, compared with the size of the object.
Define organelles
small structures within cells, each of which has a specific function
What is a photomicrograph
photograph of an image seen using an optical microscope
Define resolution
the clarity of an image; the higher the resolution the clearer the image
What is an optical microscope
A microscope that uses Light as its Radiation source and produces 2D images in colour.
Maximum Resolution of an optical microscope
0.2nm
Maximum magnification of an optical microscope
x1500-2000
Advantages of using an Optical microscope
- Easy to use
- Can observe live specimens
- Colour images
- Portable
- Cheap
Disadvantage of optical microscope
- 2D images
2. Very small organelles such as Ribosomes cannot be seen
What is a Transition Electron Microscope [TEM]
Transition Electron Microscopes use Electrons as it’s radiation source and they produce images 2D image in greyscale
Maximum Resolution of a Transition Electron Microscope
0.2um
Maximum Magnification of a Transition Electron Microscope
x500,000
Advantages of a Tranmission Electron Microscope
- High Magnification
Disadvantage of a Tranmission Electron Microscope
- Greyscale Images
- Expensive to use
- Requires Training to use
- 2D greyscale images
- Live Specimen cannot be used
What is a Scanning Electron Microscope?
Scanning Electron Microscopes use Electrons as it’s radiation source and they produce 3D images in colour
Maximum Resolution of a Scanning Electron Microscope
0.2um
Maximum Magnification of a Scanning Electron Microscope
x100,000
Advantage of Scanning Electron Microscope
- 3D Colour Images
Disadvantages of Scanning Electron Microscope
- Live specimen cannot be used
- Expensive
- Requires special training
What are confocal laser scanning microscopes
They are used to obtain high image resolution at a particular depth.
What is light interference
Some microscopes use light interference, rather than light absorption to produce a clear image without staining
What are stains
Stains are colored chemicals that bind to molecules in or on the specimen making it easier to see
What is differential staining
Some stains bind to specific structures e.g Iodine in potassium iodide solution stains cellulose in plant cell walls yellow and starch granules blue/black
