Understanding the Microscope

Honors Biology

Compound Microscope

• Contains a combination of two lenses

Eyepiece or ocular lens• Lens closest to the

eye

Objective Lens• Lens closest to the

specimen or object

How to figure out magnification

• Eyepiece X objective = Magnification • 10x X• 10x X• 10x X

Nosepiece• Objectives fastened

to this revolving structure

Stage• Where you place

your slide

Stage clips• Hold slide in place

Body Tube• Light travels through

here

Light Source• Provides light

Diaphragm• Regulates the light

reaching the objective lens

Base• Supports the

microscope

Arm• Holds the body

tube, acts as a handle

Coarse focusing knob• Used to focus under

low power only

Fine focusing knob• Used to focus under

high power only

A microscope reverses and inverts the image of an object seen under it

ee

Before viewing under the microscope

While viewing under the microscope

Things moving under a microscope are actually moving in the opposite direction

Things moving under a microscope are actually moving in the opposite direction

Stereomicroscope• Binocular

microscope

• Object is seen in

3-D

• Only used to see large objects

• Does not reverse or invert images

Transmission Electron Microscope

• Uses a beam of electrons instead of light rays

• 200,000x magnification• tissues have to be sliced

really thin, dry and in a vacuum chamber

• can’t be used with living material

Scanning Electron Microscope

• provides images with 3-D quality

• can’t be used with living material

Micromanipulator

• Used to dissect cells, can remove nuclei

• Knowledge of cells has been increased by manipulation and dissection of cells

High – Speed Centrifuge

• Spin at high speeds

• Cell components sort out at different layers according to density

Microscopic Measurements

• Use the unit called the micrometer

• 1/1000 of a meter

How to convert millimeters to micrometers

• Multiply by one thousand…or

• Move the decimal point 3 places to the right