1. History
During the 1st century AD (year 100), glass had been invented . Romans experimented with different shapes of clear glass and one of their samples was thick in the middle and thin on the edges. They discovered that if you held one of these “lenses” over an object, the object would look larger.

2. 1590, two Dutch spectacle makers, Zaccharias Janssen and his father Hans put several lenses in a tube and saw object near the end of the tube appeared to be greatly enlarged, they invented the compound microscope, a microscope that uses two or more lenses. 

3. Anton Von Leeuwenhoek of Holland became very interested in lenses grinding them smaller with greater curvatures resulting in magnifications up to 270X. With his new improved microscope he was able to see things that no man had ever seen before like bacteria, yeast, blood cells and many tiny “wee beasties” swimming about in a drop of water. From his great contributions, many discoveries and research papers, Leeuwenhoek ( ) has since been called the "Father of Microscopy".

4. Types of Microscopes
Electron Microscopes: Use beams of electrons instead of visible light, very high resolution and depth of field in images
Scanning Electron(SEM)
10x-500,000x, scans surfaces
ANT
BLOOD
FOLLICLE
MITE
POLLEN
It lives in your
eyelashes!

5. Transmission Electron(TEM): up to 10,000,000X
Beam penetrates object shows interiors
Can you name these
cell organelles?
MITOCHONDRIA
GOLGI
ROUGH ER
CELL MEMBRANE

6. The Invention that Changed the World!
Microscope
The Invention that Changed the World!

7. Light Microscopes Compound Light Stereo light
Light travels up through the
object mounted on a slide
Very small
translucent
specimens
Light travels down from top
onto object no slide is used
Large opaque objects.
SKIN CELLS vs
SKIN ON FINGER

8. 4x to BODYTUBE 10x Brings object into view NEVER used on M and H
CONDENSER narrows
beam of light below slide

9. The Objective Lenses
Mounted on the revolving nosepiece, these lenses allow the object’s image to be magnified to different powers without having to use different microscopes. Make sure the lens used is above the condenser and ‘clicked’ into place!

10. Total Magnification
Calculated by multiplying the eyepiece magnification by the objective lens magnification…
EYEPIECE
OBJECTIVE TM
10X 4x
40x
10x
100x
40x
400x

11. The Diaphragm
Disk under the stage that adjusts the amount of light. Widens or narrows the beam. Alters contrast not focus!
#1=low light #5=max light
Read by looking down at the
numbered edge of the disk
at front of the stage. Adjust with
index finger by rotating the
disk to the desired setting
The diaphragm/condenser alters light similar to the way a pencil alters a drawn line:
Very sharp = thin, crisp edges, high contrast
Very dull = wide, rough edges, low contrast

12. Field of View Area viewed within the eyepiece. Round circle of light.
Field of view decreases as magnification increases, so it is very important to always re-center your object before rotating to M or H power

13. Depth of Field
The ability of a microscope to focus on different levels, one at a time.
Look carefully…
how many cell layers
can you see?
Which layer is in focus?