Electron and light miscroscopes

TEM microscope

transmission electron microscope, used to examine thin slices or sections of cells or tissues. 2D and electrons go through the specimen to show inside it

SEM microscope

• scanning electron microscope, large depth of field, so can be used to examine the surface structure of specimens.

• 3D and shows very detailed images.

• works by bouncing electrons off the surface of the surface of a specimen that has had an ultra thin coating of heavy metal applied

the light microscope

used to study living cells and for regular use when relatively low magifiication and resolution is enough

magnification

the magnified image is produced by two lenses, an eyepiece and an objective lens,

total magnification

magnification of eyepiece * magnification of objective lens

magnification of the image

size of the image/ size of real object

limits of the light microscope

• very high magnifications are not possible, the highest magnification possible is around *1500

• low resolution, the resolving power of a light microscope is around 0.2micrometres, or 200nm

the light microscope

• can be viewed in colour

limits of the electron microscope

• can’t show colour, however colour can be added

electron microscopes

• high magnification

• high resolution