2. Introduction to the Microscope  Care  Parts  Focusing

3. Always carry with 2 hands: arm + base Only use lens paper for cleaning; still not clean? Ask your teacher! Do not force knobs Always store properly: Correct cupboard, cord neat, covered Keep a clear work area while using Stools out of the way

4. Eyepiece (Ocular lens) Body Tube Revolving Nosepiece Arm Objective Lenses: low, medium, high Stage + Aperture Stage Clips Coarse Focus Fine Focus Base Diaphragm Light Source

5. Properly set up Microscope Place the Slide on the Microscope Use Stage Clips Adjust Nosepiece to the lowest (shortest) setting Look into the Eyepiece Use the Coarse Focus

6. Follow steps to focus using low power Click the nosepiece to the medium, focus; then go to the high power objective Only use the Fine Focusing Knob on High magnification

7. Obtain a clean slide, coverslip, specimen Place a drop or two of water on the slide Transfer specimen to the slide Hold the coverslip at the edge of the water at a 45 o Angle; carefully drop the coverslip into place Air bubbles? Tap gently with pencil.

8. Prepare your slide; obtain tissue & stain Add a drop of stain to one side of the coverslip; from the other side of the coverslip, draw the stain into the slide.

9. Multiply the magnification on the ocular lens with the magnification on the objective lens. That’s it! Ocular = 20x Objective = 10x Total Magnification = 200x

10. You have to know the diameter of your Field of View (that’s the circle of light you see when you look through the ocular) Low = 4 mm or 4000  m Med = 1.6 mm or 1600  m High = 0.4 mm or 400  m 1 mm = 1000  m

11. Focus on your specimen, then estimate how many would fit across the field of view. Cell size = Field diameter/Your estimate These Diatoms have been focused under medium power, 100x Field Diameter = 1600  m How many of the selected Diatom can fit in the field of view? 7 Size of 1 Diatom = 1600/7 = 228  m Or 1.6 mm / 7 = 0.228 mm

12. Try it with these leaf cells at High Power: Elodea leaf, high power, 400x Field Diameter = 400  m Estimate = 8 Size of 1 Cell = 400/8 = 50  m

13. Now try it with these White Blood cells at High Power: Elodea leaf, high power, 400x Field Diameter = 400  m Estimate = 12 Size of 1 Cell = 400/12 = 33.3  m