electron microscope

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Electron Microscope: 

Electron Microscope Dr. Pradnya Gajbhiye

Electron Microscope: 

Electron Microscope • In 1932, invented by E. Ruska et al. • In 1986, Ruska received the Nobel Prize

PowerPoint Presentation: 

Complex, costly Technically difficult to maintain Principle Closely parallel to optical micrroscope

Electron Microscope: 

Electron Microscope beams of electrons are used to produce images wavelength of electron beam is much shorter than light resulting in much higher resolution

PowerPoint Presentation: 

Best resolution obtained 3-5 A o i.e. 0.3-0.5 mµ

Specimen Preparation: 

Specimen Preparation analogous to procedures used for light microscopy for transmission electron microscopy, specimens must be cut very thin specimens are chemically fixed and stained with electron dense material

use TEM grids: 

use TEM grids

Other preparation methods: 

Other preparation methods shadowing coating specimen with a thin film of a heavy metal Negative staining potassium phosphotungstate uranyl acetate

The Scanning Electron Microscope: 

The Scanning Electron Microscope uses electrons reflected from the surface of a specimen to create image produces a 3-dimensional image of specimen’s surface features

Newer Techniques in Microscopy: 

Newer Techniques in Microscopy confocal microscopy scanning probe microscopy -have extremely high resolution -can be used to observe individual atoms

Confocal Microscopy: 

Confocal Microscopy confocal scanning laser microscope laser beam used to illuminate spots on specimen computer compiles images created from each point to generate a 3-dimensional image

Scanning Probe Microscopy: 

Scanning Probe Microscopy atomic force microscope sharp probe moves over surface of specimen up and down movement of probe is detected and used to create image Study of surface structure of bacteria

Immunoelectron microscopy : 

Immunoelectron microscopy Allows identification several Ag Electron dense labelling of F c portion of specific Ab Anti-immunoglobulin reagent