1. Tools and Techniques of the Biologist

2. The Microscope

3. The Parts of the Microscope
Ocular
(A)
Body Tube
(B)
Course Adjustment
(I)
Nose Piece
(C)
High Power Objective
Fine Adjustment
(D)
40x
(J)
Low Power Objective
(E)
10x
Arm
Stage
(K)
(F)
Clips
Diaphragm
(L)
(G)
Light Source
(H)
Base
(M)

4. The Parts of the Microscope Compound Light microscope
two
___________________________ - uses _______________ lenses. One lens enlarges the specimen and the second magnifies it even more. Specimens must be ______________________.
Parts of the compound Light Microscope.
____________________ - is used to “look through” and is closest to the eye. Usually magnifies _______________.
_______________ - lens closest to the _______________. Usually magnifies at _______________.
_______________ - rotating piece that holds the _______________.
_______________ - holds eyepiece lens at top and objective lenses at the bottom.
_______________ - platform that holds the specimen to be examined.
Thin and transparent
Ocular or eye piece
10x
Objective lens
specimen
10x to 50x
nosepiece
objectives
Body tube
stage

5. The Parts of the Microscope
clips
_______________ - holds glass slide in place.
_______________ - regulates the amount of _______________ that reaches the specimen.
_______________ - reflects and focuses _______________ on the specimen.
_______________ - holds the _______________ and _______________.
_______________ - supports the microscope.
_______________ - large knob used for _______________ of the specimen with the _______________ objective.
_______________ - small knob used for _______________ with low power objectives and for all focusing with the high power objective.
diaphragm
light
mirror
light
arm
tube
stage
base
Course adjustment
Rough focusing
Low power
Fine adjustment
Fine focusing

6. The Parts of the Microscope
_______________ - to determine the total magnification of the microscope, multiply the magnification of the _______________ by the magnification of the objective lens.
Example: Ocular = 10x
Objective = 40x
Total Magnification: _____ X _____ = _____
_______________ - the ability of the microscope to show two points that are close together, as separate images. This is another name for _______________.
magnification
ocular 10 40
400
resolution
Sharpness of image

7. Viewing Objects under the Microscope
Low power
Position the specimen under the _______________.
Make sure the _______________ is at its _______________ (allows the most light through).
Focus under low power using the __________________ first, and then the _______________ to sharpen the image if needed.
Scan the field of view under low power.
Switch to high power checking to make sure the high power lens does not hit the slide. Focus under high power using the _______________ only.
As magnification increases, the size of the image _______________.
_______________ - what you see when you look through the ocular.
As magnification increases, the field of view _______________.
diaphragm
Maximum opening
Course adjustment
Fine adjustment
Fine adjustment
increases
Field of view
decreases

8. Viewing Objects under the Microscope
Upside downs and backwards
The image is always viewed __________________________.
As power of the objective increases, the brightness _______________.
Moving the slide to the right causes the image to move to the _______________. Moving the slide to the left causes the image to move to the _______________.
Moving the slide up causes the image to move _______________. Moving the slide down causes the image to move _______________.
decreases
left
right
down up

9. Measuring under the Microscope

10. Dissecting microscope
Other Microscopes
Electron microscope
_______________ - uses beams of _______________. It can magnify objects greater than 200,000 times. It is used in studying _______________ structures of cells. The specimen must be _______________. Living specimens would be killed by processes that are used to prepare the sample.
_______________ or _______________ - magnifies _______________. Has an ocular and objective for each eye. Gives a _______________ view of the image. Used during _______________ and to study external structures of small plants and animals.
electrons
detailed
Dead
stereomicroscope
Dissecting microscope
5x – 20x 3D
dissections

11. Technique centrifuge ultracentrifuge
_______________ and _______________ . An instrument which separates suspensions according to the _______________ of the suspended materials. An Ultracentrifuge is used to separate cell parts such as the nucleus and mitochondria out of cells.
Microdissection instruments: Small instruments used With the help of _______________ for laparoscopic surgery and for removal of _______________.
density
The microscope
Cell parts

12. Staining Materials Needed Clean glass slide Distilled water
Sample for staining
Plant: such as onion skin
Animal: human cheek cells
Cover slip
Staining agent
Iodine: used for plant cell staining
Methylene Blue: used for animal cell staining
Note: staining will kill the plant or animal cell sample being used
Two eye droppers
One for water
One for staining agent
Paper towel

13. Start with a clean glass slide
Step One – the Slide
Start with a clean glass slide

14. Place a few drops of water in the center of the slide
Step Two – the Water
Place a few drops of water in the center of the slide

15. Place sample to be stained in center of the slide over the water
Step Three – the Sample
Place sample to be stained in center of the slide over the water

16. Step Four – the Cover Slip
Place cover slip over sample to be stained at 45o angle to the slide

17. Add a few drops of stain (like iodine) to the edge of the cover slip
Step Five – the Stain
Add a few drops of stain (like iodine) to the edge of the cover slip

18. Step Six – the Draw
Put a piece of paper towel on the other edge of the cover slip to draw the stain across

19. Step Seven – the Staining
As the stain moves under the cover, it stains the sample

20. Stained sample is complete
Step Eight – Done
Stained sample is complete

21. Tissue Culture and Sterilization
______________________________ is a technique used to maintain living tissue or _______________ in a laboratory setting for further study.
_______________ culture taken at the doctor’s office.
_____________________________ fertilization. Embryos are kept alive and grown in a laboratory setting.
______________________________ can be a tissue culture for mosquitos.
_______________ the process of _______________ all the microorganisms.
Use of an _______________ sterilizes dental and surgical tools at very high temperatures.
microorganisms
throat
In vitro
Stagnant water
sterilization
killing
autoclave

22. Indicators
_______________ . Scientists use indicators which are chemicals that ______________________________ in the presence of certain other substances.
_______________ turns blue-black in the presence of starch.
______________________________ which changes from blue to brick red in the presence of glucose when heated.
_______________ paper which changes color in the presence of an acid or a base.
Bromothymol Blue which changes from blue to yellow in the presence of _______________.
Indicators
Change color
iodine
Benedict’s Solution pH
Carbon dioxide

23. Chromatography
_______________ a technique used for analyzing the chemical make-up of a mixture. This technique separates substances based on their chemical or physical properties.
Various _______________will form. Each band of color indicates a separate substance in the test material.
chromatography
Bands of color

24. Electrophoresis
_______________ is a technique to separate substances according to size, shape, and electric charge. This technique is called _______________.
Gel Electrophoresis
DNA Fingerprinting

25. Steps in Gel Electrophoresis
DNA
Extract the __________ (genetic material) from various kinds of tissue such as blood, skin, hair, semen, or saliva
The DNA is cut into different size pieces by using a special type of protein called a ____________________
The solution containing the DNA fragments is then placed in __________ on a flat plate of gel, and an ______________________ is passed through the gel plate
Since DNA has a ___________ charge, it is ___________ to the ___________ electrode
The smaller the fragment of DNA, the ___________ and ___________ it moves.
This forms a ___________ that will be matched against a known sample of DNA.
Restrictive enzyme
wells
Electric current
negative
attracted
positive
faster
farther
fingerprint

26. Steps in Gel Electrophoresis