1. PRACTICAL 1 BY NANA ABOAGYE ACHEAMPONG
CELL STRUCTURE (BIOL 151)
PRACTICAL 1 BY
NANA ABOAGYE ACHEAMPONG

2. OUTLINE GENERAL LABORATORY PRACTICES PRECAUTIONS
HANDLING OF MICROSCOPE
IDENTIFICATION OF VARIOUS PARTS OF THE MICROSCOPE
FOCUSSING

3. GENERAL LAB PRACTICE 1

4. GENERAL LAB PRACTICE

5. GENERAL LAB PRACTICE 2

6. GENERAL LAB PRACTICE 3

7. 4 5 6 GENERAL LAB PRACTICE Never carry out unauthorized experiments
Come to the lab prepared
Follow directives strictly 5 6

8. MICROSCOPE CARE

9. PICK UP
Always carry the microscope with 2 hands…..one on the arm and the other under the base in an upright position

10. SET UP
Place the microscope at least 6 inches from the edge of your laboratory table (or flat surface).
6 inches

11. SET UP Don’t bang the microscope
Clean only with a soft cloth/ tissue (preferably with a lens paper)

12. SET UP
Do not tamper with or remove any part.

13. SET UP
Do not handle the lenses with your fingers.

14. SET UP
Do not allow liquids, particularly acids and alcohol, to come into contact with any part of the microscope

15. SET UP
Always use a cover glass when examining objects or organisms mounted in water or other fluids.

16. SET UP
Always lower the stage sufficiently before placing a slide on or removing a slide from the microscope stage.

17. PACK UP
Remove immersion oil from the microscope with lens paper

18. PACK UP
When disconnecting the light source, do not pull on the wire, but grasp the plug firmly to remove it from the socket.

19. PACK UP
After use, wrap the wire around its base; send it back to the place of storage and cover it with its protective case.

20. Microscope Anatomy & Physiology
Head
Body

21. OCULAR (EYEPIECE) Uppermost series of lenses.
Magnifies the image of the specimen

22. INTERPUPILLARY ADJUSTMENT
In-between the ocular lenses
Facial adjustment.

23. BODY TUBE (BARREL) Main cylindrical part
Holds oculars, conducts light rays from specimen.

24. REVOLVING NOSEPIECE
Movable, usually circular plate at bottom of body tube.
Holds objectives in place.

25. SCANNING OBJECTIVE Shortest objective, usually magnifies 4x.
Magnifies the specimen.
Resolves the specimen

26. LOW POWER OBJECTIVE
Short intermediate- sized objective, usually magnifies 10X.
Magnifies the specimen.
Resolves the specimen

27. HIGH POWER OBJECTIVE
Long intermediate sized objective, usually magnifies 40x.
Magnifies the specimen.
Resolves the specimen

28. OIL IMMERSION OBJECTIVE
Longest objective, usually magnifies 100X
Magnifies the object.
Resolves the specimen

29. PROPERTIES OF THE OBJECTIVE LENSES
Parfocal
Alignment of all objectives along the same focal plane

30. MECHANICAL STAGE
Platform upon which specimens for examinations are placed.
Specimen support and manipulation.

31. STAGE CLIPS & SLIDE HOLDER
Located on top of the stage
Control devices which permit movement of slide.
Manipulation of specimen’s location.

32. APERTURE Hole in the centre of the stage.
Opening in the condenser unit.
Allows light penetrations through the specimen.

33. CONDENSER Lens system located below central stage opening.
Concentrates and directs light beam through specimen.

34. CONDENSER

35. COMPLEX SYSTEM OF LENSES

36. IRIS DIAPHRAGM
Located beneath stage in association with condenser unit, controlled with a lever.
Regulates brightness or intensity of light passing through lenses.
Field and Aperture diaphragm.

37. COARSE ADJUSTMENT KNOB
Generally located below stage.
Use for preliminary and coarse focusing by raising or lowering the stage.

38. FINE ADJUSTMENT KNOB
Located below stage, usually at the centre of the coarse adjustment knob.
Used for final or fine focussing by raising or lowering the stage

39. CONDENSER ADJUSTMENT KNOB
Control knob located below stage
Used to obtain full illumination by raising or lowering condenser.

40. STAGE ADJUSTMENT KNOB Located below the stage
Used to manoeuvre the specimen (stage) sideways and back to front.

41. BASE Heavy, bottom portion on which instrument rests.
Microscope support.

42. ARM Somewhat curved portion of microscope used in carrying instrument.
Microscope support.

43. LIGHT SOURCE
Situated at the base, directly beneath the condenser unit.
Diascopic (from below).
Emits light rays through the specimen to produce an image.

44. LIGHT INTENSITY CONTROL
Located at the base.
Regulates the intensity of light.

45. ON/OFF SWITCH
On the side of the base.
Turns light source on or off.

46. COMMON VOCABULARY OF THE MICROSCOPE
Magnification
Resolution
Contrast
Image size
Image details
Image distinction

47. TOTAL MAGNIFICATION Total magnification 10 x 4 = 40 10 x 10 = 100
Ocular power multiplied by objective power
Total magnification
10 x 4 = 40
10 x 10 = 100
10 x 40 = 400
10 x 100 = 1000
Ocular = 10x
Scanning = 4x
Low = 10x
High = 40x
Oil = 100x

48. FOCUSSING THE MICROSCOPE

49. FOCUSSING THE MICROSCOPE
Wipe all lenses with lens paper.
Move the scanning objective into working position.
Connect your light source and turn it on.

50. FOCUSSING THE MICROSCOPE
Mount your specimen slide on the mechanical stage.
Using the stage control knobs, move the specimen to the centre of the condenser opening in the stage.
Using the coarse adjustment knob, raise the stage to the upmost limit.

51. FOCUSSING THE MICROSCOPE
Using the condenser adjustment knob, raise the condenser as far as it will go.
While looking into the ocular, use the diaphragm lever to regulate illumination.
Locate your specimen. Using the coarse and fine adjustment knob, move the stage downward to focus.

52. FOCUSSING THE MICROSCOPE
To change objectives, simply turn the nosepiece to bring the desired objective into place. ie. PARFOCAL
Observe with both eyes.

53. AFTER USING THE MICROSCOPE
After use, the ff. steps should be performed:
Remove any slide from the stage.
Clean the instrument to remove any fluid from specimens.
Open the diaphragm.
Raise the condenser to its highest position.
Move the scanning objective into working position.
Wrap the electrical cord around the base.
Return the microscope to its proper storage place.
Cover it.

55. MICROSCOPIC TECHNIQUES
Use depth of field and/ or depth of focus to highlight features.
Use the diaphragm to improve upon image quality.
Use the stage calibrations for quick re- focusing.

56. THANK YOU!!!