1. Anton van Leeuwenhoek

2. Anton van Leeuwenhoek (1600’S) -created 1 st microscope. He noticed that if he placed 2 magnifying lenses at proper distances from one another, very small objects could be magnified.

4. Stereoscope (binocular microscope) 2 eyepieces

5. Compound Microscope (monocular microscope) 1 eyepiece a minimum of 2 lenses

6. Both are light microscopes.

7. Field of view: the circle of light one sees in the microscope.

8. the ability of a microscope to produce contrast and detail. Resolution:

9. Magnification: find by multiplying magnifying powers of lenses Example: 10x times 4x = 40x (eyepiece) (objective) (total mag.)

10. Holding Your Microscope Caring for Your Microscope

11. Carry by the base & the arm …two hands.

12. Place on desk with the arm facing you. arm you

13. Clean lenses with lens paper only.

14. Store Properly! – Remove & clean slides – Put ­­­­4x objective in place – Wrap cord gently around cord holder – Place in correct location, with cover on, and arm facing out

15. Report misuse to teacher. Teacher.

16. Slide boxes Slide box and # should match your microscope number Should have 2 clean slides + coverslips There is a fee for broken slides…$

17. How to focus the Microscope Move the low power (4x) objective into place Use the coarse adjustment to bring the stage to the objective While looking into the ocular, turn the coarse adjustment until the object comes into focus If necessary, use the fine adjustment to sharpen the focus

18. Focus at Medium Power… Move the slide to the area you wish to look at Move the 10x objective into place Adjust the focus with the COARSE then the FINE adjustment

19. Focus at High Power… Move the slide to the area you wish to look at Move the 40x objective into place (it will be tight!) Use ONLY FINE adjustment to focus!

20. How to prepare a Wet-Mount Slide: Obtain a clean slide + coverslip Place specimen in the MIDDLE of slide Using medicine dropper, place a drop of water on the specimen Place one edge of coverslip so that water touches it + it is at 45 degree angle Slowly lower coverslip, being careful not to trap air bubble -Gently tap coverslip with eraser if bubbles are trapped -Remove excess water with paper towel

21. How to Stain a Slide 1.Prepare a wet-mount, make sure that there are no bubbles 2.Add a drop of stain at the edge of the coverslip 3.Touch a small piece of paper towel on the opposite edge of the coverslip 4.The paper towel causes the stain to be drawn under coverslip Some common stains: Methylene blue, Lugol’s Iodine, Fuchsine, Wright’s

22. Measuring with the Microscope First, find the diameter of the field of view: 1. Obtain a ruler piece and focus on the millimeter markings at LOW (4x) power 2. Align the ruler’s edge across the diameter of the field of view. 3. Record the length in millimeters and convert the length to micrometers (  m) or microns. ___1000___  m = ___1___mm Diameter at LOW POWER = _________________________  m 4. Calculate the diameter at HIGH POWER using this equation: Diameter at HIGH power = (Diameter at LOW x 40)/400 Diameter at HIGH POWER = _________________________  m

23. Second, Observe the object you are measuring at either Low or High Power: 1. Estimate how many objects would fit side-by-side across the diameter. 2. Size of the object = __Diameter at observed power (  m)___ # of objects that fit Example: How big is a single pepperoni on this 16” pizza?