1. HANDLING, OPERATION & CARE OF THE LIGHT COMPOUND MICROSCOPE PRACTICAL 1

2. OBJECTIVES  IDENTIFICATION OF THE VARIOUS PARTS OF THE MICROSCOPE  DEMONSTRATION OF THE PROPER METHODS OF: CARRYING, USING, AND PRESERVING THE MICROSCOPE  DEFINITION OF SOME COMMON TERMINOLOGIES

3. HANDLING  PICK UP  SET-UP  PACK UP

4. PRECAUTIONS  Always carry the microscope by the arm and the base in an upright position and closer to the body.

5. PRECAUTION CONT.  Place the microscope at least 6 inches from the edge of your laboratory table.  Do not tamper with or remove any part.

6. PRECAUTION CONT.  Do not handle the lenses with your fingers.  Clean the lenses of the microscope with lens paper ONLY, before and after use.

7. PRECAUTION CONT.  Use a clean, soft, linen cloth to remove dirt, dust or other materials from parts other than the lenses  Do not allow liquids, particularly acids and alcohol, to come into contact with any part of the microscope

8. PRECAUTION CONT.  Always use a cover glass when examining objects or organisms mounted in water or other fluids.  Remove immersion oil from the microscope with lens paper.

9. PRECAUTION CONT.  Always lower the stage sufficiently before placing a slide on or removing a slide from the microscope stage.

10. PRECAUTION CONT.  When disconnecting the light source, do not pull on the wire, but grasp the plug firmly to remove it from the socket.

11. PRECAUTION CONT. After use, wrap the wire around its base; send it back to the place of storage and cover it with its protective case. After use, wrap the wire around its base; send it back to the place of storage and cover it with its protective case.

12. IDENTIFICATION OF MICROSCOPE COMPONENTS OCULAR (EYEPIECE) Uppermost series of lenses. Uppermost series of lenses. Magnifies the image of the specimen Magnifies the image of the specimen

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

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

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

16. SCANNING OBJECTIVE Shortest objective, usually magnifies 4x. Shortest objective, usually magnifies 4x. Magnifies the specimen. Magnifies the specimen. Resolves the specimen Resolves the specimen Use coarse and fine knobs Use coarse and fine knobs

17. LOW POWER OBJECTIVE Short intermediate-sized objective, usually magnifies 10X. Short intermediate-sized objective, usually magnifies 10X. Magnifies the specimen. Magnifies the specimen. Resolves the specimen Resolves the specimen Use the coarse and fine knob. Use the coarse and fine knob.

18. HIGH POWER OBJECTIVE Long intermediate sized objective, usually magnifies 40x. Long intermediate sized objective, usually magnifies 40x. Magnifies the specimen. Magnifies the specimen. Resolves the specimen Resolves the specimen Use fine knob only. Use fine knob only.

19. OIL IMMERSION OBJECTIVE Longest objective, usually magnifies 100X Longest objective, usually magnifies 100X Magnifies the object. Magnifies the object. Resolves the specimen Resolves the specimen Use fine knob only Use fine knob only

20. PROPERTIES OF THE OBJECTIVE LENSES Working DistanceWorking Distance — Distance between the front surface of lens and surface of cover glass or specimen in focus.

21. LABELLED OBJECTIVE LENS

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

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

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

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

27. 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.

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

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

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

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

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

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

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

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

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

37. HOW TO USE THE MICROSCOPE  Wipe all lenses with lens paper.  Move the scanning objective into working position.  Connect your light source and turn it on.

38. HOW TO USE THE MICROSCOPE  Mount your specimen on the mechanical stage.  Move the specimen over the centre of the condenser opening in the stage.  Raise the stage to the uppermost limit below the scanning objective.

39. HOW TO USE THE MICROSCOPE  Use the condenser adjustment knob to raise the condenser to the uppermost limit.  While looking into the ocular, use the diaphragm lever to regulate illumination.  Using the coarse and fine adjustment knobs, move the stage downward to focus.

40. HOW TO USE THE MICROSCOPE  To change objectives, DO NOT MOVE THE STAGE. Simply turn the nosepiece to bring the desired objective into place. Slightly turn the fine knob, if necessary. ie. PARFOCAL  Observe with both eyes. This prevents eye strain and movement of head when observing and drawing microscopic views.

41. HOW TO USE 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.

42. COMMON VOCABULARY OF THE MICROSCOPE  Magnification  Resolution  Numerical aperture  Image larger  Image clearer  Ability of lens to gather light

43. COMMON VOCABULARY OF THE MICROSCOPE contd…  Working distance  Depth of field  Parfocality  Distance between lens & specimen in focus  Measure of displacement in focus.  All objectives in reasonable focus at the same time

44. MODIFICATION OF IMAGE QUALITY  Depth of field.  Depth of focus  Use diaphragm to select the best aperture to improve upon quality.  The size of the condenser aperture should change with changing objectives.

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

46. MEASUREMENTS  Stage calibrations  Microscopic- meter (Eg. Graticule)  For quick observation of a previously viewed specimen  To measure the actual size of a cell