i hope it will suitable for those who are new in any medical college and want to deliver lecture on microscope thanks

1. Microscope
Dr. Imran Yunus

2. Who is this?
Any guesses?

3. TOPIC
MICROSCOPE

4. • By now you know that my voice is tragically
out of order. So I can’t shout as I used to. So
just read this,
“When I lost my voice, I gained my words;
In chasing our dream, we get resurrected.”

5. OBJECT:
• To study the different parts of a
compound microscope.

7. Lets discuss the formation of a
compound microscope; what are
the different parts of a compound
microscope?

8. OCULAR LENS OR EYEPIECE:
• It is usually a set of convex lens and field lens
present in a short cylinder, which fits the top
and at the body tubes.

10. BODY TUBE:
• It is a long metallic cylinder with an eye piece
at the upper end and screw at the lower end.
It can be moved vertically by coarse
adjustment screws.

12. NOSE PIECE:
• It is a circular flat screwed attached to the
body tube which holds two or more objective
lenses of different magnitudes. It can be
rotated to bring the required objective lens
against the eyepiece.

14. OBJECTIVE LENS:
• There is usually a single lens present in a
metallic cylindrical case with engraved
magnitudes.

16. Low powered & high powered
objective
• The low powered objective lens magnifies the
image 10 times as compared to the normal
eye, it provides the maximum field for
viewing.
• The high powered objective lens magnifies the
image 40 times.

17. COARSE ADJUSTMENT SCREWS
• There are two wheels one on either side
mounted on a spiral tooth axle. They move
the body tube against stage in vertical
direction to achieve focus.

19. FINE ADJUSTMENT SCREW:
• These are two smaller knobs below the coarse
adjustments screws. They provide sharp focus.

21. STAGE
• It is a horizontal plate with a central hole
below the body tube either fixed or movable
against the objective lens. It is used to place
glass slides having a specimen to observe.

23. STAGE CLIPS:
• They are two flat metallic clips placed in the
clip holes. They hold the specimen during
observation.

25. CONDENSER
• It is a moveable or fixed lens mounted below
the stage. It converges the light source on the
object

26. IRIS DIAPHRAGM:
• it is assembly of semi lunar metallic plate
which regulates; i.e. increase or decrease the
intensity of reflected light by diameter of its
aperture.

28. MIRROR OR LIGHT SOURCE.
• It is a Plano-concave mirror fixed in a movable
holder. It reflect right upwards towards the
stage.

30. ARM OF THE MAIN BODY.
• It is a solid structure on which different parts
of the microscope are mounted and is used to
grip the microscope.

32. INCLINED JOINTS:
• It is a joint where the main body is attached to
the pillar of foot or base. It keeps the
microscope at various inclination angles to
facilitate the viewing.

33. FOOT OR BASE:
• It is the lower solid part of the instrument on
which it rests and it is horse-shoe shaped.

35. so lets try something new !
No one must feel awkward if a question is
thrown at them and they fail to answer !

36. Identify different parts of microscope!

37. What is this back ground picture? Any guesses?

38. Experiment no 7B
HEMOCYTOMETER

39. OBJECT:
• To study the Hemocytometer.

43. HEMOCYTOMETER GRID:
RED SQUARE = area: 1X1= 1 mm2, volume:
100 nl.
GREEN SQUARE = area: 0.25X0.25= 0.0625 mm2,
volume: 6.25 nl.
YELLOW SQUARE = area: 0.20X0.20= 0.04 mm2,
volume: 4 nl.
BLUE SQUARE = area: 0.05X0.05= 0.0025 mm2,
volume: 0.25 nl.
DEPTH: 0.1 mm.

44. REQUIREMENT:
• Hemocytometer (improved neubauer’s
chamber) and microscope.

45. PROCEDURE:
• Improved neubauer’s chamber is a heavy
colorless glass slide which has two vertical
grooves in the central area. The central
platform in between the two vertical grooves
is divided into two equal halves by a
transverses grove

46. Top view
Lateral view
NEUBAUR’S SLIDE
Modified from image taken from wikipedia.com

47. PROCEDURE:
• A square is marked on each half so that two
preparation may be set up simultaneously for
observation. Each of these squares has got the
counting chamber and a size of 3mm X 3mm
i.e. an area of 9mm2 Each square is divided
into nine smaller squares with a dimension of
1mmx 1mm having an area of 1mm2
.

49. • How are the counting platforms divided?

50. PROCEDURE:
• Examining the counting chamber under the
microscope we find that the four smaller
squares at the corners of counting are divided
into sixteen smaller squares each. Each of
these sixteen smaller squares has an area of
1/4X1/4 mm. i.e. an area of 1/16mm2 The corner
squares are used for white blood cell count.

52. • How are the four smaller squares at the
corners of counting chamber divided?
• For what purpose do we use the corner
counting chambers?

53. PROCEDURE:
• Examine the central square under high power
of microscope. This square is divided into 25
medium squares each of the size
1/5mmX1/5mm thus having a surface area of
1/25mm2. These medium squares are
bounded by thick lines and each is further
sub-divided into sixteen smaller squares.

55. While examining the central platform of the
counting chamber what do we find?

56. PROCEDURE:
• These smaller squares therefore are
1/20mmX1/20mm in size having an area of
1/400mm2. These squares are used for red
blood cell count. Generally the four squares at
the corners and the fifth at the center are
used

58. • What is the area of the smaller squares of the
RBC counting area?

59. PROCEDURE:
• Height of the central platform having the
counting chamber is 0.1mm less than the
ridges on either side. When a cover slip is
placed over the central platform and fluid
containing cells is examined under it,
thickness of the film is 0.1mm or 1/10mm

61. • Height of the central platform having the
counting chamber is _______mm less than
the ridges on either side?

62. Calculation For RBC Count
• 1 small square = 1/10 x 1/25 x 1/16 = 1/4000
mm3

63. Calculation for WBC Count:
• 1 squares = L X B X D
= 1mm X 1mm X 1/10 = 1/10
mm3

64. PRECAUTION
• While in use the counting chamber should be
absolutely clean.
• To observe the smaller squares under high
power, use low power first and then shift to
high power.

65. PRECAUTION
• Lenses of the microscope should be kept
spotlessly clean using a soft cloth.
• Never use the coarse adjustment of the
microscope while viewing under high power
as the chamber might be crushed.

66. • Precautions?
Who wants to give it a shot?