Microscopes

What are the two types of optical microscopes ?

Light Microscope

Laser Scanning Confocal Microscope

What are the magnificiations on a light micropscope?

10X

40X

100X

Are images 2d or 3rd of Light Microscope?

2D

How do you use a light microscope?

• Sample places on slide on stage

• Light focused to eyepipece

• Rotating objective lens changes magnification

• Low power objective lense

Does optical microscopes make colour or black and white images?

Colour

How do laser scanning confocal microscopes work?

Specimen is stained with a dye

Laser is moved across specimen causing dye to flouresce and give of light

Light passed through a narrow whole to detector giving high resolution image

What D are laser scanning confocal microscopes?

2d or 3d

What is equation to calibrate a graticle?

Number of Units X Micrometes/ units = length

What is resolution of optical micrscopes usally?

200 nm

What electron resolution usually?

0.2 nm

What are the 2 types of electron microscopes?

• Scanning Electron Microscope

• Transmission Electron Microscope

How does Scanning Electron Microscope work?

Detector picks up electron that bounces off sample

Does Scanning Electron Microscope produce 3d or 2d images?

3D

What is maximum resolution of SEM

3-10 nm

How does transmissio electron microscope work?

Detector picks up electrons transmitted through sample

More dense=more electrons absorded- making it darker

What is max resolution of TEM

0.5 nm

Are TEM 2d or 3d?

2D

What are artefacts?

objects that appear under microscope that arent part of sample

Examples of Artefacts?

• Air bubbles

• Fingerprints

• Dust

What micropscope is most common for artefacts?

Electron sometimes light

Advanatges of Electron Microscopes?

• Better magnification

• Better resoltion

Advanatges of Light Microscopes?

• Can view living specimens

• Can view colour images

What do optical microscopes and SEM both allow for?

Thick sample sections

Easier sample preparation reducing risk of artecats

What do both Laser Scanning Confocal Microscope both allow?

3D images

What do both TEM and light micrscopes both allow?

2D imaging