Brief description about types of microscopes

1. MICROSCOPY
BY RIDDHI GARACH
MSc I

2.  Microscopy is the technical field of using
microscopes to view objects and areas of
objects that cannot be seen with the naked
eye (objects that are not within the resolution
range of the normal eye).
 There are three well-known branches of
microscopy: optical, electron, and scanning
probe microscope.

3.  Phase differences occur between light altered by
an object and the unaltered light. These
differences in phase tend to contrast the object
against the background.
 There are several mathematical approaches to
phase contrast microscopy but lets consider
Barer’s quantitative treatment based on Zernike’s
vector. It is based on light passing through a
homogeneous object differing in refractive index
from the surrounding medium.
 If the objects index of refraction is greater than
the surrounding medium the light passing
through the object arrives later at its destination,
producing a phase difference.

5.  A microscope that has quartz lenses and
slides and uses ultraviolet radiation as the
illumination.
 The use of shorter wavelengths than the
visible range enables the instrument to
resolve smaller objects and to provide greater
magnification than the normal optical
microscope.
 The final image is either photographed or
made visible on a fluorescent screen by
means of an image converter.

6.  Interference microscopy is a variation of
phase-contrast microscopy that uses a prism
to split a light beam in two.
 Interference microscopy is superior to phase-
contrast microscopy in its ability.
 In differential interference contrast microscopy
(DIC), the optical path difference is determined
by the product of the refractive index
difference (between the specimen and its
surrounding medium) and the thickness
traversed by a light beam between two points
on the optical path.
 Images produced by DIC have a distinctive
shadow-cast appearance.

7. A secondary emission of visible light by an
organism, when stained with a flour dye and
bombarded with invisible UV light, constitutes
fluorescence. The use of microscopic instrument
to observe such phenomena constitutes
fluorescence microscope.
APPLICATIONS
• Determine the localisation of specific (multiple)
proteins
• Determine the shape of organs, cells,
intracellular structures
• Examine the dynamics of proteins
• Study protein interactions or protein
conformation
• Examine the ion concetration etc.

9.  THEORY
 Is based upon the fact that electrons can be
refracted, reflected, and focused. In short
electrons exhibit some of the properties that light
exhibits.
 It was discovered that electrons produce 100,000
times shorter wavelengths than light.
 Electron microscopes are used to investigate the
ultra structure of a wide range of biological and
inorganic specimens including microorganisms,
cells, large molecules, biopsy samples, metals, and
crystals. Industrially, electron microscopes are
often used for quality control and failure analysis.
Modern electron microscopes produce electron
micrographs using specialized digital cameras and
frame grabbers to capture the image.

10. ELECTRON MICROSCOPE

11. BIBLIOGRAPHY
• Steve D. Wilson- Applied and Experimental
Microscopy (Burgess Publication Company).
WEBLIOGRAPHY
• https://www.google.co.in/search?q=microscopes+types&hl=
en&biw=939&bih=602&site=webhp&source=lnms&tbm=isch
&sa=X&ved=0ahUKEwjciPPtmcrPAhVMOY8KHSHiB88Q_AUIBig
B – for images
• https://en.wikipedia.org/wiki/Microscope