Types of microscopes
First review @September 12, 2023
Practise Q's Done
Transmission Electron Microscope (TEM)
a beam of electrons is transmitted through a specimen
the beams are focused to produce an image of the specimen
TEM’s have a magnification of x5,000,000 and a resolution of 0.1nm
microscope has very good quality
TEM’s can only view dead organisms
this is because electron microscopes rely on staining to create a contrast so that the
specimen can be viewed in more detail and so that organelles and cells can be
distinguished and identified
Scanning Electron Microscope (SEM)
a beam of electrons are sent across the surface of a specimen, rather than being
transmitted through them
this is called topography
only an image of the outside of the cell is produced
SEM’s have a magnification of x5000 and a resolution of 10nm
SEM’s can also only view dead organisms because they are a type of electron microscope
Laser Scanning Confocal Microscope
a single spot of light is moved across a specimen
the parts of the specimen that are stained with a dye will emit fluorescent light which will
be detected
this reflected light from the microscope is focused onto the detector by a confocal
pinhole
only the light radiated from the distance that gives the sharpest focus is detected
Types of microscopes 1
First review @September 12, 2023
Practise Q's Done
Transmission Electron Microscope (TEM)
a beam of electrons is transmitted through a specimen
the beams are focused to produce an image of the specimen
TEM’s have a magnification of x5,000,000 and a resolution of 0.1nm
microscope has very good quality
TEM’s can only view dead organisms
this is because electron microscopes rely on staining to create a contrast so that the
specimen can be viewed in more detail and so that organelles and cells can be
distinguished and identified
Scanning Electron Microscope (SEM)
a beam of electrons are sent across the surface of a specimen, rather than being
transmitted through them
this is called topography
only an image of the outside of the cell is produced
SEM’s have a magnification of x5000 and a resolution of 10nm
SEM’s can also only view dead organisms because they are a type of electron microscope
Laser Scanning Confocal Microscope
a single spot of light is moved across a specimen
the parts of the specimen that are stained with a dye will emit fluorescent light which will
be detected
this reflected light from the microscope is focused onto the detector by a confocal
pinhole
only the light radiated from the distance that gives the sharpest focus is detected
Types of microscopes 1
