Different microscopes

Types of electron microscopes

Transmission electron microscope

Scanning electron microscope

Transmission electron microscope

• Beam of electrons transmitted thru a specimen & focused to produce an image

• Highest resolution

• Produces 2D image

Scanning Electron Microscope

• Beam of electrons sent across surface of specimen, reflected electrons are collected 

• Res. less than TEM, higher than Light 

• Produces 3D images

Light vs Electron

Artefact

A visible structural detail caused by processing the specimen

Laser scanning confocal microscopy

• Moves a single spot of focused light across a specimen

• Causes fluorescence dyes from components to give off light

• Emitted light filtered thru pinhole

  • Only light radiated from v. close to focal plane is detected

• Less mag. than light, higher res than light

Fluorescent tags

• Source fluorescent proteins from deep sea organisms

• Use antibody-antigen tech to attach to outside of cells

• GFP attach to antibodies 

• Allow antibodies to attach to organisms of specimen