Microscopes

• Uses a number of lenses to veiw image
• Light passes from bulb then through condenser lens through to specimen
• Has 4 objective lenses to veiw specimen at different magnifications, x4, x10, x40 and x100

Advanategs:

• Has maximum magnification of x1500
• Specimen such as living organism can be veiwed

Disadvategs:

• Resolution of 200nm
• If two objects are close together they are seen as one object

Consists of transmission electron microscope and scanning electron microscope

Transmission of electron microscope (TEM)

• Produces 2D image
• Has magnification of x500 000
• Electons pass through dense part of samples less easier, giving contrast

Scanning electron Microscope (SEM)

• Produces 3D image
• Has maginfication of x100 000
• Electrons do not pass through the specimen, they bounce off the sample

Advanatges:

• Maximum resolution of 0.2nm
• Can be used to see inside cells

Disadvantages:

• Samples have to be placed in vacuum as electron beams are deflected by the molecules in the air
• Expensive
• Require high skill to use
• Final image is always black and white, color can be added with the use of specialised computer software