Light microscope
- 1. LIGHT MICROSCOPE Presented by :- Prajapati Jinal V . CBO :- 406 M.Sc Sem :- 2 Department of life sciences , H.N.G.U., Patan
- 2. CONTENT • What is Microscope ? • Light Microscope Introduction Principle Types of light microscope Application of light microscope
- 3. What is Microscope ? • A microscope is an instrument used to see object that are too small to be seen by the naked eye . Microscopy is the science of investigating small object and structures using such an instrument . • There are two type of the microscope : 1. Light Microscope 2. Electron Microscope
- 4. Light Microscope Introduction :- • In 1590 F.H. Janssen & Zacharias Jansen constructed the first simple light microscope . • When molecular detail is not required ,the light microscope is an ideal, and hence essential, instrument for a biologist . • The simplest form of light microscope consists of a single glass lens in combination . • All modern light microscope are made up of more than one glass lens in combination .
- 5. Principle :- • The light microscope operates on the principle that light energy will pass through and around a thin object , such as a microorganism and with the aid of lenses , form a magnified impression on the visual sensory layer of the eye . • The main components of the compound light microscope include a light source that is Focussed at the specimen by a condenser lens . • The source of light is usually the Sun or ambient indoor light .
- 6. How does light microscopy work ? • Light microscope are compound microscope , which means they contain at least two lenses . • Lenses are curved pieces of glass or plastic that bend rays of light and can magnify objects, making them appear bigger than they actually are . • Light microscope shown here magnifies an object in two stages . • Light from the mirror is reflected up through the specimen, or object to be viewed, into the powerful objective lens, which produce the first magnification .
- 7. • The image produced by the objective lens is than magnified again by the eyepiece lens, which act as a simple magnifying glass . • The magnified image can be seen by looking into the eyepiece lens. • Important factor in light microscopy include : 1. Magnification 2. Resolution 3. Contrast
- 9. Types of Light microscope :- 1. Bright - field Microscopy 2. Dark – field Microscopy 3. Phase contrast Microscopy 4. Fluorescence Microscopy Phase contrast Microscopy :- • Phase contrast microscopy first described in 1934 by Dutch physicist Frits Zemike . • A Phase contrast microscope makes it possible by utilizing two characteristics of light, diffraction and interference, to visualize specimens based on brightness differences .
- 10. Principle :- • The Principle of Phase contrast microscopy is based on the wave nature of light rays and the fact that light rays can be in phase or out of phase . • In a Phase contrast microscope, one set of light rays comes directly from the light sources . • The other set comes from light that is reflected or diffracted from a particular structure in the specimen .
- 11. How does Phase contrast microscope work ? • Light that does not interact with the specimen is collected by the objective, passes through the Phase plate ring , and is retarded exactly ¼ wavelength . • The Phase shifted is not detectable by the eye so the resulting image on the image plane in the microscope appears as a normal bright background . • Light passing through one material & into another material of slightly different refractive index or thickness will undergo a charge in phase .this charge in are translated into variations in brightness of the structures .
- 14. Application of Light Microscope • The light microscope can be used to provide information about the activity of cells and to look at very small structures such as nanostructures . • Different adaptations can help to enhance images , such as phase contrast microscopy , which provides contrast between cells and the solution they are in . • Light microscope is a great use in pathology labs so as to identify diseases. • Light microscopy can be used to explore the time and space related dynamics of molecules .
- 15. • Light microscopy has a number of applications in different sectors including in gemmology , metallurgy and chemistry . • In terms of biology , it is one of the least invasive techniques for looking at living cells . • Phase contrast microscope is most useful for examining intracellular components of living cells at relatively high resolution . • Students in schools and colleges are benefited by the use of a light microscope for conducting their academic experiments . • It is widely used in microbiology and tissue culture research to detect bacteria, cellular organelles or for testing cell and organelle preparations for lysis .
- 16. REFERENCES • Principles and Techniques of Biochemistry and Molecular Biology : by:- Keith Wilson John Walker https://en.m.Wikipedia.org https://www.dkfindout.com
- 17. THANK YOU