Microscopy

Micoscopy

The microscope is the first powerful tool used in biological studies

Microscope is the instrument to magnify minute object , there are many different version of microscope present today era are

1.   Bright light Microscope :-

Most common microscope used today’s biologist

It having two lenses system, The ocular lens (eye piece) & object lens

It visible light range is between 4000-7000 Å wavelength

It able to magnify upto about a thousand times of actual size

The resolution power of the eye is about 0.1mm , while that of microscope is 200mm

The resolving power of the microscope is determine by Abbe Equation

2.   Dark Field microscope :-

      Commonly used for achieving a marked contrast between living organisms and the background dark field microscopy

In these sample is viewed only with oblique ray , it is particularly used for studying suspension of bacteria

In these person sees those rays that are scattered from objects, it highlights specimens against dark background

3.   Phase Contrast Microscope :-

    Zernicke (1932) introduced the phase of principle contrast microscopy

He was awarded By Nobel Prize for that discovery

These microscope enhances the contrast between cells & their environment & between internal organelles & their surroundings

It is commonly used for observation living or unstained cells

Person can see mitochondria, mitotic division , nucleoli & other organelle quite clearly than other in these

4.   Interferance Microscope :-

   Like phase contrast microscope , it functioning depend on functioning in the speed of the light passes through different materials.

It has wider applications, it is relatively easy to vary contrast between & colour effect

It is mainly used for quantitative determinations, such for obtain dry weight

It has highly accurate optical balance, unlike phase microscope

5.   Polarizing Microscope :-

It is mainly used to viewing highly ordered objects such as crystal or bundles of parallel filaments

The mitotic spindle formation can be studied by these microscope

6.   Ultraviolet microscope :-

    It uses shorter UV rays for shorter wavelength (1500-3500 Å)

It lens composed of fused quartz , calcium fluoride or lithium carbonate

It is used for Qualitative & quantitative determination of nucleoplasm

7.   Cofocal scanning Light Microscope :-

    In late 1950s Marvin Minsky invented revolutionary new instrument, which is produce an image of a thin plane situated within much thicker specimen

The Specimen is illustrated  by a finely focused laser bean scans across the specimen at a single depth

8.   Flourescence Microscope :-

     It uses UV light with higher wavelength stimulation on cell components

It is most often used to detect specific proteins & other molecule in cells & tissue

In these a very powerful & widely used technique used is to combine fluorescent dyes to antibody molecules

In these two common fluorescent dyes are used Flourescein (Gives green) & Rhodamine (Gives red)

Types Of Microscopes

9.   Electron Microscope :-

M.Kholl & E.Ruska (1932) invented the electron microscope.

It is ideal instrument for studying cellular infrastructure

There are two major electron microscope are employed are Transmission electron microscope & Scanning electron microscope

Transmission electron microscope is most common used in these electron microscope

Scanning electron microscope especially useful for examining the surface of specimens

10.                     Scanning Tunnelling Microscope :-

     It is invented by two scientists Gerd Bening & Heinrich Rohrer (1981)

It produces bumps &valleys of the atoms on the surface of object

Mapping of surface done by “Feel” much as blind person explores the surface of ground by tappng a cane

Gerd Bening & Heinrich Rohrer got Nobel prize (1986) for inventing Tunelling micoscope