Types CarePartsUsing

Nosepiece

• First microscopes were simple scopes– One magnifying lens (i.e. one magnifying glass)

• Compound Microscopes– Two magnifying lenses & a source of light

• Dissection Microscopes– Low magnification (cannot see cells)– Used for dissection to get a better look at the larger

specimen

• Scanning electron microscope (SEM) – Extremely detailed 3D views of the surface of the

specimen (think of “S” for surface)– Specimens are coated with metal

• Transmission electron microscope (TEM)– Electrons pass through the specimen - can view

internal structure (think of “T” for through)– Specimen must be sliced into an extremely thin section

- 20-100 nm and stained with metals

Blood cell

Bacteria

Termite

SEM images

Ballpoint pen

Mitochondrion

Bacterium

Rough ER

Chloroplast

TEM images

• Always carry with 2 hands

• Never allow cords to hang over the counter

• Do not force knobs

• Always use the fine focus if on any power higher than scanning (4X)

• Loosely wrap the cord around the scope for storage

• Never place on top of the vent in front of your station!

Ocular Lens- Eyepiece

Revolving NosepieceArm

Objective Lens

StageStage Clips

Coarse Adjustment Focus

Fine Adjustment Focus

Base

Diaphragm

Light Source

Coverslip

Slide

• Turn the microscope on• Lower stage• Click Nosepiece to the shortest setting (4X)• Place the Slide on the Microscope• Use Stage Clips • Look into the Eyepiece• Use the Coarse Focus to slowly bring

specimen into focus• Bring specimen into focus using Fine Focus knob• Adjust diaphragm if necessary

• Follow steps to focus using low power• Carefully turn the nosepiece to the next

longest objective• Do NOT use the Coarse Focusing Knob• Use the Fine Focus Knob to bring the

specimen into focus

When Finished Observing

• Bring stage all the way down • Turn nosepiece so that

smallest objective is directly over the slide

• Carefully remove the slide!

Microscope Terms

• Magnification• Resolution• Field of View• Depth of Focus• Image Inversion

Magnification• Making an image appear larger than its actual size• For example: magnification value of 100X means an

image appears 100 times larger than its actual size• Total Magnification = objective mag. x ocular mag.

– Example: 40X mag. (objective) times 10X mag. (ocular) = total of 400X mag.

Resolution• The ability of a microscope to show the details

of an object, ability to distinguish between 2 lines

• The higher the resolution the clearer the image

– Both high magnification and good resolution are needed to view the details of extremely small objects clearly.

Focusing on an Object

• Remember: Locate and Focus on your object with the scanning (smallest) objective lens first

• This provides:Greater Depth of Focus – depth of 3D objects (layers)Greater Field of View – how much of the image you can see