Metric measurement and microscopy
Dec 28, 2015
Metric units of length
Length: meter (m), centimeter (cm), millimeter (mm), micrometer (µm), nanometer (nm)
1m=100cm 1cm=10mm 1mm=1,000 µm 1µm=1,000nm
1m= 1×102cm= 1×103mm= 1×106 µm= 1×109nm
1nm= 1×10-3µm= 1×10-6mm= 1×10-7cm= 1×10-9m
Microscopy
• Microscopes
Illumination source
MagnificationSliced section
imageThree dimension
image
Lightmicroscope
light rayslower (2000times)
regular light microscope stereo-microscope
Electronmicroscope
electron beams
higher (over500,000 times)
transmissionelectronmicroscope(TEM)
scanning electronmicroscope (SEM)
Use of the compound light microscope
• Pick up the microscope carefully
• Never touch the lens with fingers.
• Use ONLY lens paper to clean the glass
• Don’t loss the key
The compound light microscope
• Two sets of lenses
—the ocular lenses
—the objective lenses
• The light only passes through clear portions, not opaque portions
• The objects must be small or thinly sliced sections
Focusing the compound light microscope
• Always begin focusing with the lowest power objective
• Use coarse-adjustment knob ONLY with low-power objective
• Make sure the nosepiece is on the lowest power objective when done with the scope assignment
• Clean all slides, materials and work area