1. Tools of a Scientist and Introduction to the Microscope
Students will have their microscopes out, for reference as we go through each of the steps. As an introduction, students will be asked what kinds of things they can do with this tool.

2. Scientific Measurements
Metric System (SI System)
Length- meter
Volume- liter
Mass- grams
Time- second
Temp.- Celsius or Kelvin
Microscopic measurements
One micron (micrometer) = millimeter
( there are 1000 microns in a millimeter)

3. Tools of the Scientist simple microscope- one lens
ex. Magnifying glass
compound microscope- two lenses
ocular system- 2 lenses
ocular
objective
total magnification = ocular x objective
mechanical system-
base clips
arm body tube
stage nose piece
slide coarse adj.
fine adj.
light system- disc diaphragm, light source

4. Tools of a Scientist
magnification- refers to enlargement in one direction
ex. 100x means 1mm will appear to be 100mm
resolution- the ability of a microscope to show 2 parts that are close together. (the sharpness of the image)
Preparation of slides
fix the specimen in a preservative
embed the sample in liquid wax or plastic and let harden
section the specimen into very thin slices with a microtome.
Stain the specimen to allow the parts to be seen better. The denser parts will pick up more stain and will appear darker.

5. Stereoscopic Microscope
Two separate monocular microscopes each with its own set of eyepiece lenses
Produce a three-dimensional image with a right-side-up, frontward orientation
Offers a large working distance for bulky items
Relatively low magnification (10x-125x)
Can be lighted from below or vertically from above
This microscope is actually two separate monocular eyepiece lenses. The objective lens is common to both microscopes.

6. Stereoscopic Microscope
Stereo Microscope
Compound
Microscope

7. Phase Contrast Microscope
used to see structures in living cells without staining, by manipulating light waves (changing speed and phase)

8. Scanning Electron Microscope
Can magnify 150,000X
Doesn’t magnify as much but can expose very fine detail.
Electrons are bounced from the surface and collected to show great depth in a 3-D fashion
Has a depth of focus more than 300X that of an optical microscope
Uses electrons rather than light
Offer much greater resolution than with a light microscope

9. Scanning Electron Microscope

10. Scanning Electron Microscope

11. Scanning Electron Microscope
The SEM shows very detailed 3-dimensional images
created without light waves.

12. Transmission Electron Microscope
300,000x (best magnification) (Needed to be invented before most cell organelles and viruses could be seen)
a. uses an electron beam and electromagnetic lenses directed through a vacuum containing electromagnets.
b. When the beam hits objects those electrons that pass through are focused on a screen.
c. Object must be dead, dried, embedded and thinly sectioned (disadvantage)

13. Transmission Electron Microscope

14. Special Microscopy Techniques
a. microdissection- micromanipulator attached to stage uses different tools to do various things:
(1) microneedles- removes organelles
(2) microelectrode- produces an electrical current .
b. chromatography- separates chemicals in a mixture by density
c. centrifugation- separates cell parts according to density by spinning
d. DNA gel electrophoresis- Separates chemicals in a mixture by size (pieces of DNA)

15. Chromatography
Centrifugation
Gel Electrophoresis

16. Microscope Care Always carry with 2 hands
Only use lens paper for cleaning
Do not force knobs
Always store in cabinet
Wipe off any water on the stage
Teacher demonstrates how to hold the microscope, where the lens paper is located and how to use it. Students will be invited to turn the knobs and observe the stage as it moves up and down. Teacher will demonstrate how to store the microscope.

17. Microscope Parts Eyepiece- magnifies Body Tube-
so light rays cross properly
Revolving Nosepiece- to rotate lenses
Arm- to carry by
Objective Lens- magnifying lenses
Stage- place slide
here
Stage clips-to hold slide
Coarse Adjustment Knob- find and focus under lower powers
This is the exact version of the microscope used in class. Students will be identifying the parts on the microscopes at their desks as we go along and what their functions are.
Diaphragm-
Regulates amount of light
Fine Adjustment knob- final
focusing under any power
Light
Base- to carry by

18. Using the Microscope Place the Slide on the Microscope Use Stage Clips
Click Nosepiece to the lowest (shortest) setting
Look into the Eyepiece
Use low power objective
Use the Coarse Adjustment Knob to focus
Give students a slide from the “common things” set, each student will practice focusing and changing objectives.

19. Using High Power Follow steps to focus using low power
Click the nosepiece to the longest objective
Do NOT use the Coarse Adjustment Knob
Use the Fine Adjustment Knob to focus on the slide
Have students exchange slides so they can look at different things, walk them through using the high power objective to focus slides. Emphasize not using the coarse objective during this process, as it will crack the slides.
What can you find on your slide?