Light Microscopes

Use lenses to direct light in order to enlarge images

Simple Microscopes

Have 1 lens.

Compound Light Microscope

Has two sets of lenses. Eyepiece Objective Lenses

Magnification

The change in apparent size. 4x 10x

Found by multiplying the power of eyepiece lens by the power of the objective lens.

Electron Microscopes Use a magnetic field in a vacuum to

direct a beam of electrons Can magnify up to 1 million times 3 types

Scanning Electron Microscope (SEM) Shows the 3-D surface of the object

Transmission Electron Microscope (TEM) Produces a 2-D image

Scanning Tunneling Microscope (STM) Shows the arrangement of atoms on the surface of

the object

Parts of a Compound Light Microscope

Parts of a Compound Light Microscope

Parts of a Compound Light Microscope

Parts of a Compound Light Microscope

Be very careful not to touch the light as it can be HOT!

Parts of a Compound Light Microscope

Parts of a Compound Light Microscope

Parts of a Compound Light Microscope

Using the Microscope

To Carry One hand on arm One hand on base Don’t tilt

Using the Microscope

To Set up Place on table with arm pointed towards you. Use the coarse adjustment knob to raise the

nosepiece all the way up. Click the low objective lens into place by turning

the nosepiece (Do not turn the nosepiece by grasping the objective lenses!)

Adjust the diaphragm until you see a bright circle of light

Using the Microscope

To Clean Lenses Only clean with lens paper!

Using the Microscope

Preparing a slide: Caution: Glass!

Place a small drop of water on the slide. Place the “e” in the drop of water. Hold a cover slip at an angle to one side

of the water drop. Slowly drop the cover slip onto the slide,

trying to avoid air bubbles.

Using the Microscope

To View a Specimen With the nosepiece raised all the way up,

place a slide over the circular hole in the stage.

Secure the slide with the stage clips. Looking at the side of the microscope,

lower the objective lens until it is almost touching the slide using the coarse adjusting knob.

Using the Microscope

To View a Specimen (cont.) Looking through the eyepiece, slowly raise the

objective lens. Never lower the objective lens while looking through the eyepiece!

When you can see the specimen, use the fine adjustment knob to bring the image into sharp focus.

When moving to a higher power, always look to the side to make sure lens doesn’t hit the slide.

To Use a Microscope

To put away the microscope Raise the objective lens all the way up

before removing slide. Place the slide on your table. Loosely wrap the cord around the base of

the microscope. Be very careful not to touch the light as it is

HOT! Cover with a dustcover.

How to Use a Microscope

To put away the microscope (cont) Carry properly to cupboards. Never put the microscope on its side. Clean the slide and cover slip with

water...be careful not to drop as they are glass and will cut fingers!

Place the slide cover slip on the paper at the front of the room to dry.