MICROBIOLOGY
Types of microscope
and their functions
, ◼️INTRUDUCTION:
Microscope, instrument that produces enlarged images of small objects, allowing
the observer an exceedingly close view of minute structures at a scale convenient
for examination and analysis. Although optical microscopes are the subject of this
article, an image may also be enlarged by many other wave forms,
including acoustic, X-ray, or electron beam, and be received by direct or digital
imaging or by a combination of these methods. The microscope may provide
a dynamic image (as with conventional optical instruments) or one that is static (as
with conventional scanning electron microscopes).
The magnifying power of a microscope is an expression of the number of
times the object being examined appears to be enlarged and is a dimensionless
ratio. It is usually expressed in the form 10× (for an image magnified 10-fold),
sometimes wrongly spoken as “ten eks ”—as though the × were an algebraic
symbol—rather than the correct form, “ten times.” The resolution of a
microscope is a measure of the smallest detail of the object that can be
observed. Resolution is expressed in linear units, usually micrometres (μm).
The most familiar type of microscope is the optical, or light, microscope, in
which glass lenses are used to form the image. Optical microscopes can be simple,
consisting of a single lens, or compound, consisting of several optical components
in line. The hand magnifying glass can magnify about 3 to 20×. Single-lensed
simple microscopes can magnify up to 300×—and are capable of revealing bacteria
—while compound microscopes can magnify up to 2,000×. A simple microscope
can resolve below 1 micrometre (μm; one millionth of a metre); a compound
microscope can resolve down to about 0.2 μm.
Types of microscope
and their functions
, ◼️INTRUDUCTION:
Microscope, instrument that produces enlarged images of small objects, allowing
the observer an exceedingly close view of minute structures at a scale convenient
for examination and analysis. Although optical microscopes are the subject of this
article, an image may also be enlarged by many other wave forms,
including acoustic, X-ray, or electron beam, and be received by direct or digital
imaging or by a combination of these methods. The microscope may provide
a dynamic image (as with conventional optical instruments) or one that is static (as
with conventional scanning electron microscopes).
The magnifying power of a microscope is an expression of the number of
times the object being examined appears to be enlarged and is a dimensionless
ratio. It is usually expressed in the form 10× (for an image magnified 10-fold),
sometimes wrongly spoken as “ten eks ”—as though the × were an algebraic
symbol—rather than the correct form, “ten times.” The resolution of a
microscope is a measure of the smallest detail of the object that can be
observed. Resolution is expressed in linear units, usually micrometres (μm).
The most familiar type of microscope is the optical, or light, microscope, in
which glass lenses are used to form the image. Optical microscopes can be simple,
consisting of a single lens, or compound, consisting of several optical components
in line. The hand magnifying glass can magnify about 3 to 20×. Single-lensed
simple microscopes can magnify up to 300×—and are capable of revealing bacteria
—while compound microscopes can magnify up to 2,000×. A simple microscope
can resolve below 1 micrometre (μm; one millionth of a metre); a compound
microscope can resolve down to about 0.2 μm.
