1. Microscopy and Cytology

2. Compound Light Microscope
Review proper use and care of microscope by watching video.
Principles of microscopy p 78

3. A.Magnification
Factor by which specimen is enlarged

4. B. Parfocal and parcentric
Image will remain in focus and centered as you switch from one objective to the next.

5. C. Size of microscopic field
Using a ruler, you will measure the diameter of the field using 4X scanning objective.
Your measurement will be somewhere near 4.2 mm
Ruler is in mm. Convert to micrometers
4200 micrometers (um)

6. Formula to determine unknown field of view if field of view of scanning objective is known.

7. 4200 um 40 X X Total magnification of unknown field
Total mag with scanning objective
Field of view of scanning objective
4200 um
40 X X
Total magnification of unknown field

8. 4200 um 40 100 X Total magnification with low power objective
Total mag with scanning objective
Field of view of scanning objective
4200 um 40 X
100
Total magnification with low power objective
Answer: 1680 um

9. Calculating the field of view
Objective mag
Ocular mag
Total mag
Diameter (mm)
Diameter (um)
Scan 4X
10X
40X
4.2
4200
Low
100X
N/A
1680
High
400X
420
Oil
1000X
168

10. If the size of bacterial cells is in the range of 1-10 micrometers, which objective should be used for viewing bacterial cells?

11. D. Depth of focus
Defined as the vertical distance that an object remains in focus at one time.
Remember to focus on each individual thread to determine which is on top.

12. E. Image orientation View the letter E slide
If you place the slide face up and right side up on the stage, how does the “e” appear when viewed through the microscope?

13. F. Resolving Power
Degree at which 2 points on a specimen are seen as separate images

14. G. Contrast
The degree to which details of a specimen stand out against the background

15. Omit section “V. Other types of microscopes”

16. Microscopy Answer questions on microscopy on p 84-86.
Label parts of microscope.
You will need to know these concepts for the lab practical.

17. Part II:The Cell p 89
Review information on cellular structures and organelles. This material will be a review of what you have covered in lecture.
For the lab practical, I will only ask questions about the structures that we view in the lab.

18. Exercise 7.5 p 95
Look over drawing and models of plant and animal cells.
Concentrate on identifying these structures:
Nucleus, nucleolus, plasma membrane, cytoplasm, chloroplast (in plant cells), cell wall (in plants), vacuole, cilia, flagella

19. Exercise 7.6 p 96 A. Cyanobacteria-omit
B. Elodea leaf- prepare a wet mount, view and sketch (use a drop of water, then add safranin)
C. Onion leaf- prepare wet mount using iodine. Use a very thin section. Draw and label.
D. Stained cheek cell- prepare wet mount stained with methylene blue. Draw and label.
E. Ear swab- omit

20. Cheek cells at 10X

21. Cheek cell at 1000X (using 100 X oil objective)

23. All photos by Jeff Beck, CCCCD unless otherwise noted.

24. Onion cell

25. Exercise 7.7 Bacterial slides p.102
You must use OIL IMMERSION objective to view bacteria.
If you are not sure how to use oil, ask!
Find the area to view using scanning, 10X and 40X objectives, then add oil and move to 100X objective.
Always find the area with scanning objective first, then move to higher magnifications
Detailed instructions for using the oil immersion objective

26. View prepared slides of bacterial cells. Gram-stain
Purple- gram positive
Pink to red- gram negative
Cell shapes
Coccus
Bacillus
Spirillum

27. Rods- bacillus

28. Spherical-coccus

29. Corkscrew- spirillum

30. p103 Study drawing of bacterial cell
Answer lab questions #2 and #3 on p