1. Tools of a Biologist

2. Microscopes: number one tool of a biologist
Small -to view
Function: microscope are instruments used to view very small objects.
In biology we will use it to view….
living cells and unicellular organisms.

3. Compound Light Microscope

4. There are 3 types of microscopes used in biology:
1. Compound light microscope
-Compound-
look through 2 lenses at the same time in order to properly magnify the organism.

5. Compound light microscope:
-light must pass through the
diaphragm and through the
object.
-object must be “thin” or
transparent so the light can
pass through it.
-Diaphragm:
regulates the amount of light that can pass through.
-Best setting of the diaphragm is #2

7. Total magnification: low power: ocular lens x10 low objective x4
x40
medium power:
low objective x10
x100
high power:
low objective x40
x400

8. Limit of Resolution
-is the point at which you see an item most clearly.
Any magnification above or below that point will results in the object looking blurry.

9. Type 2: Stereoscope
-Used to view the surface of objects which are too large for light to pass through them.
-Uses 2 lights to illuminate the surface of the object.
-Stereo means
“3 dimensional”
-Provides a 3-D detailed look at the surface of an object.

11. -look through
2 ocular lenses
-magnifies between x10 to x60

12. Type 3: Electron Microscopes
Uses electrons to form an image and NOT light
Has a very high limit of resolution.
-can see items very clearly at any magnification
-can magnify up to 500,000x and still be clear
Object is placed in a vacuum
No air
No oxygen
Organism is DEAD

13. Two types of electron microscopes:
1. T.E.M. ~ Transmission Electron Microscope
Produces a 2-D, black and white image of inside of a cell.

15. 2. S.E.M. ~ Scanning Electron Microscope
Produces a 3-D, black and white image of the surface of an object.

16. Staining The purpose is to:
add color to a cell so that the cell and its structures can be seen more clearly through a microscope.

18. Additional tools of a biologist:
Tool used to separate the components of a mixture by their different densities.
Chromatography:

20. Link to graphing