Electron Microscopy and its type Transmission electron microscopy

Electron microscopy and type s

1. ELECTRON MICROSCOPY Bhalerao Sainath Sub. T.- Tiwari S.

2. WHAT ARE ELECTRON MICROSCOPES ? Electron microscope are scientific instruments that use highly energetic electron to examine objects on a very fine scale as, Topography ( Surface features) Morphology ( Size and Shape ) Crystallographic Information (arrangements of atoms)

3. INVENTION OF EMs To study objects of < 0.2 micro meter For analysis of sub cellular structure Study of cell organelles Cell metabolism An Ems can magnify structure from 100-250000 Times than light microscope.

4. TYPES OF ELECTION MICROSCOPE There are two types of Ems, Transmission Electron Microscope (TEM) – Allows one to study inner structure of objects Scanning Electron Microscope (SEM) – Used for visualise the surface of objects

5. TRANSMISSION ELECTRON MICROSCOPE TEM was discovered by Max Knoll and Ernst Ruska in 1931. TEM is a Microscopy technique where a beam of electrons is transmitted through an ultra thin specimen. An image is formed from the interaction of the electrons transmitted through vthe specimen TEM provides morphological and crystalline info. The images allows researchers to view specimen on a molecular level by making it possible to analyse structure and texture.

6. APPLICATIONS OF TEM Ideal tool for the study of ultra structure of cells Plant Cell

7. Used in identification of plant and animal viruses

8. ADVANTAGES OF TEM TEM offer the most powerful magnification, potentially over 1 million times or more TEMs provides information on element and compound structure Images are high quality and detailed They are easy to operate with proper training

9. SCANNING ELECTRON MICROSCOPE ( SEM ) SEM electron microscope is an improved model of an electron microscope SEM is used for the study three dimensional image of the specimen SEM produces images of a specimen by scanning the surface with focused beam of electrons SEM gives 3D structure of objects

10. APPLICATION OF SEM SEM is very useful to view the surface structure of microscopic specimen like bacteria, diatoms, pollen grains and others . Basillus megatherium

11. SEM is employed in the analysis of structural features of compound eyes of insects

12. ADVANTAGES OF SEM Better resolution Work with low voltage Fast imaging Easy to operate