Microscopes are instruments designed to produce magnified images of small objects. They must accomplish three tasks: produce a magnified image, separate details in the image, and render details visible. There are different types of microscopes including simple, compound, stereoscopic, electron, scanning electron, and transmission electron microscopes. Electron microscopes use a beam of electrons instead of light to magnify images and can achieve higher magnifications than light microscopes. Confocal laser scanning microscopes use a laser beam to generate 3D images of thick specimens.

1. Microscopy - an introduction
• Microscopes are instruments
designed to produce magnified
visual or photographic images of
small objects.
The microscope must accomplish three tasks
1. produce a magnified image of the specimen
2. separate the details in the image,
3. render the details visible to the human eye or camera.

2. Scale

3. Microscope
One or more lenses that make an enlarged image of an
object.

4. Simple Microscope
• Light passes through only 1 lens.
• Example: magnifying glass

5. Compound Microscope
• Lets light pass through an object and then
through two or more lenses.

6. Stereoscopic Microscope
• Gives a three dimensional view of an
object. (Examples: insects and leaves)
• Used for dissections

7. Electron microscopes – use a beam of
electrons instead of a beam of light to
magnify the image

8. Electron Microscopes
• can achieve 3D images using electrons

9. The Scanning Electron Microscope
• produces a 3-dimensional image of
specimen’s surface features
spider head of a butterfly

10. Scanning electron microscopy (SEM)
Types of specimens:
-Whole organisms
-Natural tissue surfaces
-Exposed tissue structure
A flea magnified 50 000 X
What is this?

11. Scanning
Electron
Microscope

12. Transmission electron
microscopy (TEM).
• Allows the observation of molecules within
cells
• Allows the magnification of objects in the
order of 100, 000’s.

13. Transmission electron microscope (TEM)
– Provides for detailed study of the internal
ultrastructure of cells
– a beam of electrons Longitudinal Cross section
section of of cilium 1 µm
is transmitted through cilium
the specimen for
a 2D view
Figure 6.4 (b) cilia on rabbit lungs

14. Transmission electron microscope
Chloroplast from a tobacco leaf H1N1 virus

15. Confocal Laser Scanning Microscope
(CLSM)
• laser beam used to
illuminate spots on
specimen
• computer compiles
images created from
each point to generate
a 3-dimensional image
• used on specimens
that are too thick for a
light microscope

16. A, B, C pollen grains: Scanning electron microscope
D pollen grains: Confocal Laser Scanning Microscope
E pollen grains: Transmission electron microscope
F pollen grains: Light microscope
G Mixed pollen grains (bright field light microscope, stained) H pollen grains
confocal laser scanning microscope

17. Look at the
following
micrographs (a
picture made by a
microscope) and
try to determine
what the object
is!

18. DENTIST’S DRILL

19. TOILET PAPER

20. HYPODERMIC NEEDLE

21. VELCRO

22. STAPLE THROUGH PAPER

23. BLACK WIDOW SPIDER CLAW

24. PORCUPINE QUILL

25. MASCARA BRUSH

26. ANT

27. BLACK FLY

28. MOSQUITO

29. CAT FLEA

30. MITE FEEDING

31. POLLEN GRAIN

32. ANT EYE

33. APHID ON A LEAF

34. EYELASHES

35. DOG FLEA

36. H1N1 VIRUS

37. What is the difference between a…
VIRUS and CELL?
E.coli bacterial cells

38. VIRUS BACTERIA
- can’t live on its own- must - can exist on its own
live inside another cell
- much smaller (20 – 400nm) - larger (1000 nm = 1μm)
- none are beneficial - some can be beneficial
(bacteria in gut)
- no cell wall, only a protein - outer cell wall
coat
- cannot be killed by antibiotics - are killed by antibiotics