The document provides an overview of the history and development of the microscope from 1000 AD to the present. It describes key inventors and their contributions, such as Leeuwenhoek who was the first to observe and describe bacteria in the 1670s. The document also outlines the main parts of the microscope and their functions, including the objectives, eyepiece, stage, mirrors, and controls for adjustment. It provides examples of different microscope types and their applications in science.

1. Introduction to the
Microscope
• History
• Types
• Care
• Parts & functions
• Focusing

2. Circa 1000AD –
The first vision aid
was invented
(inventor unknown)
called a reading
stone. It was a glass sphere that
magnified when laid on top of reading
materials.

3. Circa 1284 –
Italian, Salvino D'Armate is credited
with inventing the first wearable eye
glasses.

4. 1590 – Two Dutch eye glass makers,
Zaccharias Janssen and son Hans Janssen
experimented with multiple lenses
placed in a tube. The Janssens observed
that viewed objects in front of the tube
appeared greatly enlarged, creating both
the forerunner of the compound
microscope and the telescope.

5. 1665 – English
physicist, Robert
Hooke looked at a
sliver of cork
through a
microscope lens and
noticed some
"pores" or "cells" in
it.

6. 1674 – Anton van Leeuwenhoek built a
simple microscope with only one lens to
examine blood, yeast, insects and many
other tiny objects. Leeuwenhoek was the
first person to describe bacteria, and he
invented new methods for grinding and
polishing microscope lenses that allowed
for curvatures providing magnifications of
up to 270 diameters, the best available
lenses at that time.

7. 18th century – Technical innovations
improved microscopes, leading to
microscopy becoming popular among
scientists. Lenses combining two types
of glass reduced the "chromatic effect"
the disturbing halos resulting from
differences in refraction of light.

8. 1830 – Joseph Jackson Lister reduces
spherical aberration or the "chromatic
effect" by showing that several weak
lenses used together at certain distances
gave good magnification without
blurring the image. This was the
prototype for the compound microscope.

9. 1872 – Ernst Abbe, then research
director of the Zeiss Optical Works,
wrote a mathematical formula called the
"Abbe Sine Condition". His formula
provided calculations that allowed for
the maximum resolution in microscopes
possible.

10. 1903 – Richard
Zsigmondy developed
the ultramicroscope
that could study
objects below the
wavelength of light.
He won the Nobel
Prize in Chemistry in
1925.

11. 1932 – Frits Zernike
invented the phase-
contrast microscope
that allowed for the
study of colorless and
transparent biological
materials for which he
won the Nobel Prize
in Physics in 1953.

12. 1931 – Ernst Ruska co-invented the
electron microscope for which he won the
Nobel Prize in Physics in 1986. An
electron microscope depends on electrons
rather than light to view an object,
electrons are speeded up in a vacuum
until their wavelength is extremely short,
only one hundred-thousandth that of
white light. Electron microscopes make

13. 1931 – Ernst
Ruska
it possible to
view objects
as small as
the diameter
of an atom.

14. 1981 – Gerd Binnig and Heinrich Rohrer
invented the scanning tunneling
microscope that gives three-dimensional
images of objects down to the atomic
level. Binnig and Rohrer won the Nobel
Prize in Physics in 1986. The powerful
scanning tunneling microscope is the
strongest microscope to date.

15. •Compound Microscope
•Dissection Microscope
•Scanning Electron Microscope (SEM)
•Transmission Electron Microscope (TEM)

16. Compound microscopes are light
illuminated. The image seen with this type
of microscope is two dimensional. This
microscope is the most commonly used.
You can view individual cells, even living
ones. It has high magnification. However,
it has a low resolution.

17. Frog’s blood
1,000x
Paulownia Wood c.s.
200x

18. A dissection microscope is light
illuminated. The image that appears is
three dimensional. It is used for dissection
to get a better look at the
larger specimen. You cannot
see individual cells because
it has a low magnification.
(also called stereo
microscope)

19. Sunflower with moth
pupa in the stem
10x
Head of a moth pupa
60x

20. SEM use electron illumination. The
image is seen in 3-D. It has high
magnification and high resolution. The
specimen is coated in gold
and the electrons bounce
off to give you and exterior
view of the specimen. The
pictures are in black and
white.

21. cockroach antenna
pigeon blood

22. TEM is electron illuminated. This gives a
2-D view. Thin slices of specimen are
obtained. The electron beams pass
through this. It has
high magnification
and high resolution.

23. mitochondrion
bacillus bacteria
dividing

24. • Always carry with 2 hands
• Never touch the lenses with your fingers.
• Only use lens paper for cleaning
• Do not force knobs
• Keep objects clear of desk and cords
• When you are finished with your "scope",
rotate the nosepiece so that it's on the low
power objective, roll the stage down to
lowest level, rubber band the cord, then
replace the dust cover.

25. Objectives:
1. Identify the parts of the
microscope;
2. Describe what parts of the
microscope can do;

26. Materials:
• Microscope
• Activity Note book
• Learners’ Material
• Manila Paper

27. A. The Microscope, Its Parts and their
Functions
1. Get the microscope from its box or the
cabinet. Do this by grasping the curved
arm with one hand and supporting the
base with the other hand.
2. Carry it to your table or working place.
Remember to always use both hands
when carrying the microscope.
I. Activity, Analysis

28. 3. Put the microscope down
gently on the laboratory table
with its arm facing you. Place
it about 7 centimeters away
from the edge of the table.
4. Wipe with tissue paper or
old t-shirt the metal parts of
the microscope.

29. Analysis 1. What are the
functions of the base and the
arm of the microscope?
5. Figure 1 shows
a light microscope
that most schools
have. Study and
use this to locate
different parts of
the microscope.

30. 6. Look for the
revolving
nosepiece.
Note that
objectives are
attached it.
You should
know that
there are
lenses inside
the objectives.

32. Analysis 2. What have you
observed about the objectives?
Most schools have light microscopes
with three objectives. Others have four.
Usually, the shortest one marked 3x, 4x
or 5x is called the scanner. The low
power objective (LPO) is marked 10x or
12x while the high power objective
(HPO) is marked 40x, 43x or 60x. The
objectives magnify the object to be
observed to a certain size as indicated by
the 3x, 10x or 40x, etc. marks.

33. If the longest objective of
your microscope is marked 97x
or 100x or OIO or the word “oil”
on it, then it has an oil
immersion objective (OIO). This
objective is used to view bacteria,
very small protists and fungi. The
OIO requires the use of a special
oil such as quality cedarwood oil
or cargille’s immersion oil.

34. 7. Find the coarse
adjustment. Slowly turn it
upwards, then downwards.
Analysis 3. What is
accomplished by turning the
coarse adjustment upwards?
downwards?

35. 8. Looking from the side of the
microscope, raise the body tube.
Then, turn the revolving
nosepiece in any direction until
the LPO is back in position. You
will know an objective is in
position when it clicks. Note that
the revolving nosepiece makes
possible the changing from one
objective to another.

36. Analysis 4. What is the
other function of the
revolving nosepiece?
Analysis 5. Which part
connects the eyepiece to
the revolving nosepiece
with the objectives?

37. 9. Locate the eyepiece. Notice
also that it is marked with a
number and an x. Know that the
eyepiece further magnifies the
image of the object that has been
magnified by the objective. If the
eyepiece is cloudy or dusty, wipe
it gently with a piece of lens
paper.

38. Use lens paper only in cleaning
the lenses of the eyepiece and
the objectives.
Remember
10. Look through the eyepiece. Do you
see anything?
11. Now, locate the mirror. Then,
position the microscope towards diffused
light from the windows or ceiling light.
Look through the eyepiece and with the
concave mirror (with depression) facing
up, move it until you see a bright circle of
light.

39. Never use direct sunlight as a light
source to view objects under the
microscope. Direct sunlight can
permanently damage the retina
of the eye.
Caution
The bright circle of light is called
the field of view of the microscope.
Adjust the position of the mirror so
that it is not glaring to the eyes.
Practice viewing through the
microscope using both eyes open.
This will reduce eyestrain.

40. Analysis 6. What are the two
functions of the eyepiece?
Analysis 7. Describe the
function of the mirror.
12. Locate the diaphragm.
While looking into the eyepiece,
rotate the diaphragm to the next
opening. Continue to do so until
the original opening you used is
back under the hole in the
stage.

41. Analysis 8. What do you
notice as you change the
diaphragm openings?
Analaysis 9. What can you
infer as to the function of
the diaphragm?
13. Find the
inclination joint.

42. Analysis 10. What parts of the
microscope are being connected
by the inclination joint?
14. Grasp the arm and slowly
pull it towards you. Sit down
and try looking through the
eyepiece.
Tilting of the microscope allows
one to do observations while seating
down. This is however, only done
when materials observed do not
contain liquids like water.
Remember

44. Ocular lens
Body Tube
Revolving Nosepiece
Arm
Objective Lens
Stage
Stage
Clips Coarse adjustment knob
Fine adjustment knob
Base
Diaphragm
Light

45. Ocular lens
magnifies; where you
look through to see the
image of your specimen.
They are usually 10X or
15X power. Our
microscopes have an ocular
lens power of 10x.

46. arm
supports the tube and
connects it to the
base

47. stage
the flat platform
where you place
your slides

48. coarse adjustment knob
moves stage (or body
tube) up and down

49. fine adjustment knob
small, round knob on
the side of the
microscope used to
fine-tune the focus of
your specimen
after using the coarse
adjustment knob

50. base
the bottom of the
microscope, used for
support

51. body tube
connects the eyepiece
to the objective
lenses

52. revolving nosepiece
the part that holds two
or more objective lenses
and can be rotated to
easily change power

53. objective lens
Adds to the magnification
Usually you will find 3 or
4 objective lenses on a
microscope. They almost
always consist of 4X, 10X,
40X and 100X
powers. When coupled
with a 10X (most common)

54. objective lenses
eyepiece lens, we get total
magnifications of 40X (4X
times 10X), 100X , 400X
and 1000X.
The shortest
lens is the lowest power, the
longest one is the lens with
the greatest power. Lenses
are color coded.

55. objective lenses
The high power objective
lenses are retractable (i.e.
40XR). This means that if
they hit a slide, the end of
the lens will
push in (spring loaded)
thereby protecting the lens
and the slide.

56. stage clips
Stage clips hold the slides in
place. If your microscope
has a mechanical stage, you
will be able to move the
slide around by turning two
knobs. One
moves it left and right, the
other moves it up and down.

57. diaphragm
controls the amount of light
going through the specimen
Many microscopes have a
rotating disk under the
stage. This diaphragm has
different sized holes and is
used to vary the intensity
and size of the cone of light

58. diaphragm
that is projected upward into
the slide. There is no set rule
regarding which setting to use
for a particular power. Rather,
the setting is a function of the
transparency of the specimen,
the degree of contrast
you desire and the particular
objective lens in use.

59. light
makes the specimen
easier to see

60. The proper way to focus a microscope is
to start with the lowest power objective
lens first and while looking from the
side, crank the lens down as close to the
specimen as possible without touching
it. Now, look through the eyepiece lens
and focus upward only until the image
is sharp. If you can't get it in focus,
repeat the process again.

61. Once the image is sharp with the low
power lens, you should be able to
simply click in the next power lens and
do minor adjustments with the focus
knob. If your microscope has a fine
focus adjustment, turning it a bit should
be all that's necessary. Continue with
subsequent objective lenses and fine
focus each time.

62. Rotate to 40x objective, locate desired
portion of specimen in the center of the
field. Refocus very carefully so that the
specimen is focused as sharply as
possible. (Do not
alter focus for the
Following steps )

63. Partially rotate so that 40x and 100x
objectives straddle the specimen.

64. Place a small drop of oil on the slide in
the center of the lighted area. (Take care
not to dribble on the stage.)
Put the small drop
of oil directly over
the area of the
specimen to be
Examined.

65. Rotate so that the 100x oil immersion
objective touches the oil and clicks into
place.

66. Focus only with fine focus. Hopefully,
the specimen will come into focus easily.
Do not change focus dramatically.

67. Clean up!: When you have finished for
the day, wipe the 100x oil immersion
objective carefully with lens paper to
remove all oil. Wipe oil from the slide
thoroughly with a Kimwipe. Cleanse
stage should any oil have spilled on it.
Recap the immersion oil container
securely, replace in drawer.

68. Q1. What are the functions
of the base and the arm of
the microscope? The base
provides support to the
microscope. The arm on the
other hand supports the
body tube and it is where
the microscope is held.

69. Q2. What have you observed
about the objectives?
Answers can be: they are of
different lengths, they are
marked with numbers
followed by x, some may say:
there are three or four
objectives attached to the
revolving nosepiece.

70. Q3. What is accomplished
by turning the coarse
adjustment upwards?
Downwards? Turning the
coarse adjustment upwards
and downwards raises and
lowers the body tube with
the objectives respectively. It
also focuses or brings out the
object to be observed.

71. Q4. What is the other
function of the revolving
nosepiece? It facilitates
the changing of objectives.
Q5. Which connects the
eyepiece to the revolving
nosepiece with the
objectives? Body tube.

72. Q6. What are the two
functions of the eyepiece? It is
where you look through in the
microscope. It also magnifies
the image of the object that
has been magnified by the
objective.
Q7. Describe the function of
the mirror. It reflects light up
to the diaphragm, object to be
observed and lenses.

73. Q8. What do you notice as you
change the diaphragm openings?
The size of the openings differ.
The amount of light reflected also
changes in that the bigger the
opening, the greater is the amount
of light reflected.
Q9. What can you infer as to the
function of the diaphragm? The
diaphragm regulates the amount
of light reflected to the object to be
viewed.

74. Q10. What parts of the
microscope are being
connected by the inclination
joint? The arm and the base of
the microscope.
Q11. What does this
movement do? It allows one to
tilt the microscope so viewing
is possible while seated.