Parts of a Microscope and Their Functions

Arm

Curved piece of metal that holds the body tube in place over the stage and base; hold microscope by this part

Mirror or light source (lamp)

Increases the amount of light shining through your specimen

Stage

The flat surface on which you put your slide

Low-power objective lens

Magnifies the image on the slide (usually 4X)

Coarse adjustment knob

Large knob used to adjust the position of the body tube, allowing you to quickly bring your specimen into view; use this first and NEVER under high power.

Base

Heavy bottom part that supports all the other parts of the microscope; hold microscope by this

Medium-power objective lens

Magnifies the image on the slide (usually 10X)

Body tube

Light passes through this hollow tube; maintains correct distance between ocular lens and objective lenses

Stage clips

Holds the microscope slide in place on the stage

Revolving nosepiece

Holds the objectives and allows you to change the position of the objectives so that you can change magnification

Diaphragm

Changes the amount of light that enters the body tube and shines through the sample on the stage

Objective lenses

Magnifies the image on the slide; has lens and tube called a mount

Eyepiece

Also called ocular lens; allows you to see the object and magnifies the image (usually 10X)

Total magnification of microscope

Multiply Ocular lens (eyepiece) magnification (10X) by Objective lens magnification (4X, 10X, 40X on our class microscopes)= 40X, 100X, or 400X

High-power objective lens

Magnifies the image on the slide (usually 40X)