2. Introduction to the Microscope  History  Care  Parts  Focusing

4. The First Light Microscopes Around 1590 Zaccharias and Hans Janssen experimented with lenses in a tube, leading to the forerunner of the microscope and the telescope In the late 1600’s, Anton van Leeuwenhoek was the first to see bacteria, yeast, and many other microbes using a microscope

5. Images Produced by Light Microscopes AmoebaStreptococcus bacteriaAnthrax bacteria Human cheek cells Plant cells Yeast cells

6. Beyond Light Microscopes Light microscopes are limited by their resolution. –Light microscopes cannot produce clear images of objects smaller than 0.2 micrometers The electron microscope was invented in the 1930’s by Max Knott and Ernst Ruska –Electron microscopes use beams of electrons, rather than light, to produce images –Electron microscopes can view objects as small as the diameter of an atom

7. Types of Electron Microscopes Transmission electron microscopes (TEMs) pass a beam of electron through a thin specimen Scanning electron microscopes (SEMs) scan a beam of electrons over the surface of a specimen Specimens from electron microscopy must be preserved and dehydrated, so living cells cannot be viewed

8. Images Produced by Electron Microscopes Cyanobacteria (TEM) Lactobacillus (SEM) Campylobacter (SEM) Deinococcus (SEM) House ant Avian influenza virus Human eyelash Yeast

9. Always carry with 2 hands Only use lens paper for cleaning Do not force knobs Always store covered Keep objects clear of desk and cords

10. Eyepiece Body Tube Revolving Nosepiece Arm Objective Lens Stage Stage Clips Coarse Focus Fine Focus Base Diaphragm Light

11. Place the Slide on the Microscope Use Stage Clips Click Nosepiece to the lowest (shortest) setting Look into the Eyepiece Use the Coarse Focus

12. Follow steps to focus using low power Click the nosepiece to the longest objective Do NOT use the Coarse Focusing Knob Use the Fine Focus Knob to bring the slide What can you find on your slide?

13. References http://education.denniskunkel.com/catalog/ product_info.php?products_id=1123http://education.denniskunkel.com/catalog/ product_info.php?products_id=1123 http://micro.magnet.fsu.edu/ http://inventors.about.com/library/inventor s/blroberthooke.htm