electron microscope by Priyanka patel..pptx

electron microscopy

1. Topic :- Electron microscope GUIDED BY Miss Tuleswari sahu mam Ass. Prof. Of zoology PRESENTED BY Name- Priyanka patel Class- MSC ZOOLOGY II SEM Subject- tools and techniques

2. Synopsis INTRODUCTION WHAT IS MICROSCOPY ELECTRON MICROSCOPE PRINCIPLE OF ELECTRON MICROSCOPE PARTS OF ELECTRON MICROSCOPE TYPE OF ELECTRON MICROSCOPE. I. SEM II. TEM ADVANTAGES DISADVANTAGES APPLICATION CONCLUSION REFRENCE

3. INTRODUCTION The microscope magnifies the image of such objects thus making them visible to the human eye. Microscopes are used to observe the shape of bacteria, fungi, parasites and host cells in various stained and unstained preparations. There are many different microscopes available.

4. WHAT IS MICROSCOPY The electron microscope uses a beam of electrons and their wave-like characteristics to magnify an object’s image, unlike the optical microscope that uses visible light to magnify images.

5. ELECTRON MICROSCOPE • An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination.

• The wavelength of an electron can be up to 100,000 times shorter than that of visible light photons.

• Electron microscopes have a higher resolving power than light microscopes and can reveal the structure of smaller objects

6. Principle of Electron microscope Principle of Electron Microscope The lenses used in the electron microscope are magnetic coils. These magnetic coils are capable of focusing the electron beam on the sample such that the sample gets illuminated. As the flow of current increases, the strength of the magnetic lens increases.

7. Parts of Electron Microscope Electron Microscope is in the form of a tall vacuum column that is vertically mounted. It has the following components: 1. Electron gun The electron gun is a heated tungsten filament, which generates electrons. 2. Electromagnetic lenses The condenser lens focuses the electron beam on the specimen. A second condenser lens forms the electrons into a thin tight beam. 3. Specimen Holder The specimen holder is an extremely thin film of carbon or collodion held by a metal grid. 4. Image viewing and Recording System The final image is projected on a fluorescent screen.Below the fluorescent screen is a camera for recording the image.

8. Types of Electron Microscope: • There are basic 4 types of Electron Microscope: 1. Analytical Electron Microscopy (AEM)
2. Scanning Transmission Electron Microscope (STEM)
3. Scanning Electron Microscope (SEM) 4. Transmission Electron Microscope (TEM)

9. Transmission Electron Microscope(TEM) Is a microscopy technique in which a beam of electrons is transmitted through an ultra-thin specimen, interacting with the specimen as it passes through it.
A transmission electron microscope can achieve better than 50 pm
resolution and magnifications of up to about 10,000,000x

10. Scanning Electron Microscope (SEM) A scanning electron
microscope (SEM) is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons.
The electrons interact with atoms in the sample, producing various signals that contain information about the sample’s
surface topography and composition.

11. Advantages The scanning electron microscope has many advantages over traditional microscopes. The SEM has a large depth of field, which allows more of a specimen to be in focus at one time. The SEM also has much higher resolution, so closely spaced specimens can be magnified at much higher levels.

12. Disadvantages Size – Despite the advantages in technology over the years, electron microscopes are still large, bulky pieces of equipment which require plenty of space in a laboratory. Also, as electron microscopes are highly sensitive, magnetic fields and vibrations caused by other lab equipment may interfere with their operation.

13. Application Electron microscopy (EM) is a technique for obtaining high resolution images of biological and non-biological specimens. It is used in biomedical research to investigate the detailed structure of tissues, cells, organelles and macromolecular complexes.

14. Conclusion Scanning electron microscopy is a key tool to study the effect of physicochemical properties on adhesion phenomena (pH, roughness, topography, temperature, etc ).

15. Reference Wikipedia https://en. wikipedia.org/wiki/Electron_microscope Microbiology by Lansing M. Prescott.