PARTS OF LIGHT MICROSCOPE:
Eyepiece: It is present on the top of the body tube where you place your eye it is also
Nosepiece: It holds two or more objective lenses and
can allow rotation to easily change the power.
usually, there are different objective lenses on a microscope: Low power 10x
(5 – 6 mm), High power 40x (0.5 – 1.5 mm) and Oil immersion 100x
(0.15 – 0.20 mm)
Stage clips: It holds the slide in proper place
Stage: The flat platform used to place the slide
Diaphragm: It regulates the amount of light on the
Light source: it projects light
upwards through the diaphragm, slide and lenses.
Base: supports the
Condenser lens: The purpose of
the condenser lens is to focus the light onto the specimen between the
mirror and stage.
Arm:. : It is the tube connected to base of the
Coarse adjustment knob: : It is used
first to achieved an appropriate focus.
Fine adjustment knob: It is used to bring objects into perfect
OF LIGHT MICROSCOPE:
Light microscopy is the most largely used microscopy technique in
In Optical microscopy, the objects studied look darkened and the
adjacent area looks very well illuminated.
MAGNIFICATION POWER: It is fixed at the bottom of the body tube just above the
preparation under examination.
RESOLUTION POWER: the
ability of the lens to distinguish with two objects at a particular distance
The lower the resolution power, smaller the size of the object
that can be observed
Dark-field Microscope (=Ultra-microscope):
Invented by: Zsigmondy (1905).
PRINCIPLE: : The “stop” block all the light from
entering light into the object lens accept peripheral light that is reffered as
the light is reflected off the site of the specimen itself. The resulting image
is particularly stricking one that is brightly illuminated specimen surrounding
by a dark field
The most effective use of DFM is to
visualize living cells that could be distorted by drying or heat or cannot be
stain with the usuall method. It can outline the organism shape and permit
rapid identification of swimming cell that might appear in dental and other