“Microscopy is defined as, the observation of
tiny objects or those things which are not with our naked eye with the help of
Optical microscope is the first microscope which
Drebbel was the first who invented first microscope in Netherland in 1920s
But at the same
time it’s also depicted that microscope was first discovered by Hans
Janssen’s son claimed that his father also invented microscope and telescope.
After that in 1965 Giovanni Faber called microscope the name for Galileo
Galilei’s Compound microscope.
Dutch draper and scientist, it was Anton van Leeuwenhoek (1632-1723), in the
late 17th century became the first man to make and who used a real microscope.
1665, micrographia was published by Robert hooke. He gives important
illustrations regarded microscopy. Micrographia published the illustrations for
the use microscopes.
microscope as we know it today came into being is by the advancement of
technology and improved optics.
IS A MICROSCOPE? AND HOW DOES ITS WORK?A microscope is an
apparatus, a machine or an instrument used to identify small or tiny objects
which are not seen by human eye, or designed to make fine details visible. Microscopes
are used produce magnification (magnified image) resolution (separate details
in image) and contrast for the specimen.
PARTS AND SPECIFICATION
In year 1590, Zacharias Jannsen a glasses
maker discovered compound microscope.
OPTICAL OR LIGHT MICROSCOPE:
Lenses and light used in compound
microscope to magnify identify and to enlarge the image is called as optical
microscope or light microscope.
The two types of lenses for higher magnification
are used in compound microscope
The ocular lens.
A compound microscope, at the top the lens is present for see through and 10X
or 15X power lens used in compound microscope.
Tube: Tube is
used to connected the eyepiece to the objective lenses
Arm: Arm is used
to supports the tube and connected it to the base
Base: Base is the
bottom and used for supports of the microscope.
Illuminator: In microscope if mirror is present, for the immersion of
light beneath the stage. A steady light source of 110 volts present in a place
Stage: The slides we
place in the flat platform. This platform is stage. Slides are hold by stage
clips in place. The slides are moved in mechanical stage by turning two knobs. Knobs
are used for left right and up down position.
Nosepiece: A part that are
used to holds 2 or more objective lens and deviate power by revolving this
Objective Lenses: In a microscope three or more objective lens powers of 4X,
10X, 40X and 100X is present. These lenses are for examine the object.
Condenser Lens: Condenser
lens focus the light on to examine or seen the image. Condenser is for sharpen
Diaphragm or Iris: Beneath
the stage having a rotating disk in microscopes. Different sizes of perforation
are present in diaphragm and is for giving variations in intensity and size of
the cone of light.
Lenses and light used in compound microscope
to magnify identify and to enlarge the image is called as optical microscope or
The magnifying glass is simplest optical
microscope and is resolution power is good at about 10X magnification.
Common types usually found in light or
optical microscopes are,
microscope (Nomarski interference microscope).
DARK-FIELD MICROSCOPE (ULTRA-MICROSCOPE):
Lord Faraday scientifically considered the color of tiny gold particles, and he
obtained a little penetrating visions.
30 years, Richard Zsigmondy also broadly considered the estates of
nanoparticles and was rewarded by Nobel Prize.
discovered ultra-microscopy, which is known as dark field microscopy, in
partnership with Siedenkopf in 1905
Dark field microscope consists of an opaque
disk present in centre in which a special of condenser lens is used, so the
rays don’t directly pass to the objective lens. Because of this microscopy a
brighter image of a specimen is formed in dark background.
In microbiology and auto radiography, this
microscopy is used.
1. Dark field microscopy is mostly done on the
same microscope on which bright-field microscopy is done.
2. In reverse of the normal condenser it hold an
3. The disk stops light that would fall into the
objective lens without deviation.
4. Only light that has been returned or deflect by
the specimen design the picture.
5. The surrounding of field object appears dark
while the object illuminate brightly.
ADVANTAGES AND DISADVANTAGES
a. The merits of darkfield microscopy also
converts into its demerits.
b. The dark field microscopes deflect brightness
and light rays that making the details of the objects brightly.
c. Dark field light microscopes gives better
results, especially blood samples.
d. It gives immense magnifications of bacteria
and small magnifications of the tissues and cells of several species.
e. Several bacteria and fungi examined by dark
does not give good resolution.