MICROSCOPES F STEREO F COMPOUND LIGHT F TRANSMISSION ELECTRON (TEM) F SCANNING ELECTRON (SEM)

IMPORTANT TERMS F RESOLUTION- the ability to distinguish small, close objects, or to see things clearly F Human eye- sees 2 lines 1 mm apart at a distance of 5.15 m F MAGNIFICATION- ability to make an image appear larger

STEREO (Dissecting) MICROSCOPE FUFUFUFUseful for dissections FMFMFMFMagnification up to 10 X

COMPOUND LIGHT MICROSCOPE F Uses 2 lenses(Hence Compound) F Light bulb or mirror is light source F To find total magnification, multiply magnifications of 2 lenses in use F EX- eyepiece is 10 X and low power objective lens is 4 X, total magnification is 10 X 4 or 40 X

COMPOUND LIGHT MICROSCOPE F Usually limited to 1000 X total magnification - because it uses light F Can study living or dead specimens F Bacteria are the smallest living specimen that can be viewed

Compound Light Micrograph

TRANSMISSION ELECTRON MICROSCOPE (TEM) F Uses electrons to magnify specimens F Electrons pass through the specimen F Specimens must be sliced very thinly- therefore they’re dead F Specimens appear dark F Total magnification can be 1-2 million X

TEM Micrograph

SCANNING ELECTRON MICROSCOPE F Scans surface of 3D objects using electrons F Specimens are dead F Specimens coated with a metal- picture appears metallic F Can see depth F Total magnification = 300,000 X

SEM Micrograph