1. Introduction to Microscopes A lesson in the care and use of compound microscopes

2. Anton van Leeuwenhoek (1670’s) -observed first single-celled protists and bacteria with his single lens microscope Robert Hooke (1665) Published Micrographia where he coined the word “cell” in describing the cork slices and included detailed drawings Hooke’s Compound Microscope

3. Compound Light Microscope (monocular microscope) 1 eyepiece a minimum of 2 lenses (binocular microscope) 2 eyepieces

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

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

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

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

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

9. Clean lenses with lens paper only.

10. 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

11. Report misuse to teacher. Teacher.

12. Slide boxes Slide box and # should match your microscope number Should have 2 clean slides + coverslips

13. 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

14. 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

15. 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!

16. 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

17. 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