1. Simple to Complex – Life’s Levels of Organization
Our journey
begins here.

2. Introduction to the Microscope
Types
Care
Parts
Focusing
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.

3. Stereoscope
This microscope allows for binocular (two eyes) viewing of larger specimens.

4. Simple Microscope vs. Compound Light Microscope
Which kind do we use?
Lets light pass through an object and then through two or more lenses.
Similar to a magnifying glass and has only one lense.

5. Stereoscope & Light Microscopes

6. Light Microscope
light as source of
illumination
glass lenses
limited resolution (loses resolving power at magnifications above 2000X)

7. Florescent Stained Cell –shows the skeleton (green) and
Comparison of Microscopic Techniques for Visualizing a Living, Unstained Cell
Florescent Stained Cell –shows the skeleton (green) and
nucleus (purple) of the cell, etc.
Bright field
Phase-contrast

8. Higher Resolution Is Achieved by Viewing Sections of Fixed, Stained, and Embedded Samples
A microtome cutting sections of an embedded sample.

9. What can you see with a microscope?

10. Electron Microscope Uses a magnetic field to bend beams of electrons;
The two types are: Scanning and Transmission
Uses a magnetic field to bend beams of electrons;
greater magnification & resolving power than light microscope

11. Electron Microscopy
A wavelength of electron beam is much shorter than light, resulting in much higher resolution

12. Scanning Electron Microscope (SEM)
Allow scientists to view a universe too small to be seen with a light microscope.
SEMs scan the surface of a specimen to magnify 3-D objects up to 150,000x
Invented in 1965, see the 3-D surface of a specimen.

13. Scanning Electron Microscopy (SEM) Visualizes Surface Features

14. Specimen Preparation
Specimens are coated with metals to deflect electrons from a beam scanned across the sample.

15. SEM of Stereocilia Projecting from a Cochlear (inner ear) Hair Cell

16. SEM Photos!

17. Transmission Electron Microscope (TEM)
Electrons are passed through very thin specimens to see what is inside!
Invented in1933
Magnification is 500,000x

18. A TEM of an Onion Root Tip Cell

19. Confocal Scanning Laser Microscope
confocal microscopy and scanning probe microscopy
have extremely high resolution
can be used to observe individual atoms about 2,000,000x magnification

20. Confocal Scanning Laser Microscope
More images!

21. Optical sections of a pollen grain
Scanning confocal microscopy allows reconstructing a 3D image by stacking optical sections.
Stacked sections

22. Scanning Tunneling Microscope
The scanning tunneling microscope (STM) is a non-optical microscope that scans an electrical probe over a surface to be imaged to detect a weak electric current flowing between the tip and the surface.
Can find the position of individual atoms and molecules on the surface

23. Scanning Tunneling Microscope
Scanning tunneling microscope (STM) invented in 1981, is widely used in both industrial & fundamental research to obtain atomic-scale images of metal surfaces. It provides a three-dimensional profile of the surface.

24. Light Compound Microscope

25. Microscope Parts Eyepiece Body Tube Revolving Nosepiece Arm
Objective Lens
Stage
Stage Clips
Coarse Focus
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
Fine Focus
Light
Base

26. Microscope Care 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.
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.

27. Using the Microscope Place the Slide on the Microscope Use Stage Clips
Click Nosepiece to the lowest setting
(shortest objective lens)
Look into the Eyepiece
Use the Coarse Adjustment Knob to focus first then use the fine knob.
Total Magnification=
Give students a slide from the “common things” set, each student will practice focusing and changing objectives.
ocular (eyepiece) X objective lens

28. What Are Some Characteristics of Microscope Viewing?
Low power
High power
Magnification
Objective lens X Eyepiece lens
Field of view
Light intensity
Depth of field
*layers or levels penetrated 28
Less
Greater
1/18/01
Larger
Smaller
Brighter
Dimmer
More
Less

29. Tips on Good Drawings of Specimens
1. Use pencil - you can erase and shade areas.
2. All drawings should include clear and accurate labels (and be
large enough to view details), with the specimen name
(usually on slide) and magnification.
3. Labels should be written on the outside of the circle. The circle indicates the viewing field as seen through the eyepiece, specimens should be drawn to scale – i.e. if your specimen takes up the whole viewing field, make sure your drawing reflects that. All arrows should end with the point touching the object to be labeled!
last does not exist in certain plant cells).

30. Tips on Good Drawings of Specimens
100 X
400 X

31. Using High Power Follow steps to focus using low power
Click the nosepiece to the longest high objective
Do NOT use the Coarse Focusing Knob
Use the Fine Focus Knob to bring 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?

32. Which is the most powerful kind of microscope?

33. Use this animation for slide show for light, optics: lenses color etc.