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Presentation on theme: "Microscopy."— Presentation transcript:

1 Microscopy

2 Types of Microscopes: Compound Light Microscope (what we use most often) Stereoscopes – also known as dissecting scopes 3. Electron Microscopes

3 Parts of the Microscope
Arm body

4 Parts of the Microscope
Diaphragm Light Source

5 Parts of the Microscope
Stage Stage Clips

6 Parts of the Microscope
Revolving Nosepiece Objective Lenses

7 Parts of the Microscope
Ocular Lens

8 Parts of the Microscope
Coarse adjustment knob Used only when low power objective is used!!

9 Parts of the Microscope
Fine adjustment knob

10 Important Vocabulary :
magnification  \mag-ne-fe-'ka-shen\ n 1. apparent enlargement of an object 2. the ratio of image size to actual size A magnification of "100x" means that the image is 100 times bigger than the actual object. resolution  \rez-e-loo-shen\ n 1. clarity, sharpness 2. the ability of a microscope to show two very close points separately

11 Magnification ocular power = 10x low power objective = 20x high power objective = 50x What is the highest magnification you could get using this microscope ? 500x Ocular x high power = 10 x 50 = 500. (We can only use 2 lenses at a time, not all three.) b) If the diameter of the low power field is 2 mm, what is the diameter of the high power field of view in mm ?

12 8 mm The ratio of low to high power is 20/50
.8 mm The ratio of low to high power is 20/50. So at high power you will see 2/5 of the low power field of view (2 mm). 2/5 x 2 = 4/5 = .8 mm c) in micrometers ? 800 micrometers To convert mm to micrometers, move the decimal 3 places to the right (multiply by 1000). .8 mm x 1000 = 800 micrometers d) If 10 cells can fit end to end in the low power field of view, how many of those cells would you see under high power ? 4 cells. We can answer this question the same way we go about "b" above.  At high power we would see 2/5 of the low field.  2/5 x 10 cells = 4 cells would be seen under high power.

13 Carrying a Microscope

14 Steps to Use: Rotate the low power objective into place and make sure the stage is all the way down. Place slide on stage making sure object to be viewed is centered over the hole in the stage. Use the stage clips to hold the slide in place. Turn light on. Focus first with the coarse adjustment knob. Once in focus on low power, turn the nosepiece until the next higher lens is in place. Use FINE adjustment knob ONLY and focus the object.

15 Recording what you see:
Include: Figure #: and Title Labeled drawing of the field of view. Label on the right using straight lines which should never cross. Common and scientific name of organism. Magnification you were viewing when you drew the organism: ocular X objective

16 Making a wet mount:

17 Wet Mounts: Poorly Done: Nicely Done:

18 Remember: If you are seeing perfectly round, clear circles then you just may be looking at air bubbles. Check your slide and try again. Microscopes must always be properly put away. Slides and cover-slips should be washed, dried, and returned to their proper place.

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