LESSON 5: : The Compound Microscope Flashcards
is a valuable tool in the
study of microorganisms.
Microscope
Is an instrument that uses one or more lenses to produce a magnified
image of an object that is invisible to the naked eye.
is the most commonly used microscope in laboratories. It
uses the principle of light microscopy (also called optical microscope) in which it uses natural
or artificial transmitted light as the source of light to illuminate an object.
Compound microscope
Has high magnification but lower resolution resulting to a less sharp image
compared to some advanced
of a microscope is the
ability of a microscope to see a tiny object 1000 times.
Magnification
Can
see as tiny as 0.1 micrometer (μm) or 100 nanometers (nm) diameter.
Simple compound microscope
on the other hand is the ability to
distinguish details or to see two close objects as two distinct objects.
Resolution
The product of the magnification of the objective lens and that of the eyepiece.
Total magnifying power of the compound microscope
Compound microscopes can either be a monocular; consisting of a single eyepiece, or a binocular; consisting of a pair of eyepieces.
The eyepieces are the lenses you look through. In binocular
microscopes the eyepieces can be adjusted to match the distance between the eyes of
different observers.
The magnifications are usually stamped on the side of the eyepiece
(most are 10X).
Eyepiece/Ocular Lens:
: Light travels from the objectives through a series of magnifying lenses in the
body tube to the ocular.
Contains a prism that bends the light rays so that
they will pass through the oculars.
Body tube
Attached to a rotating nose piece, or turret, at the base of the body tube
are a group of 3 or 4 objectives.
Objective Lens
Objective lenses are usually named according to their magnifying power, as follows:
scanning power 4X;
low power 10X;
high power 40X;
oil immersion 100X.
Objective Lens
The surface or platform on which you place the microscope slide is the
Stage
In the center of the stage is an opening called
Stage aperture
The stage is
(—)
and has clips to hold the slide in place.
stationary
The stage is
movable and is called a
Mechanical stage
Controlled by 2 knobs located on the
top, side, or bottom of of
Movement of stage
The area under the stage, called the
, may contain a diaphragm, a
condenser, or both
Substage
Regulates the amount of light passing from the light source
through the specimen and through the lens system of the microscope.
Greatly improving your image of the specimen.
Diaphragm
The light source, usually an electric lamp, which transmits light
through a translucent object for viewing and controlled by an on/off switch. You can control
the amount of light entering the specimen by adjusting the diaphragm.
Illumination System
Is usually concave on 1 side and flat on the other
mirror
The flat side of the
mirror is usually used with the scanning and low-power objectives
Is
used with the higher power objectives. The light source for the mirror is usually a lamp;
natural light can be used but it is not preferred because its intensity is too variable.
concave mirror
You can focus your microscope by using this
Coarse and fine adjustment knobs
Uses an ultraviolet light source to expose a specimen stained with
fluorescent dye resulting in an emission of longer wavelength of light.
Fluorescent microscopes:
utilizes a beam of electrons instead of a beam of light used in the light
microscopy. The resolution of the electron microscope is extremely high, theoretically
100,000 times than that of a
Electron microscopes
a type of an electron microscope that provides a three- dimensional image of the object as well as high resolution
Scanning electron microscope:
another type of electron microscopy by which live organisms can be
visualized based on rapid cooling of specimens by deep-freezing in liquid gas and the
subsequent formation of carbon platinum replica
Freeze-etching:
