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Types of microscope Electron Microscope An electron microscope

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Electron Microscope

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Page 1: Types of microscope Electron Microscope An electron microscope
Page 2: Types of microscope Electron Microscope An electron microscope

Types of microscopeTypes of microscope

Page 3: Types of microscope Electron Microscope An electron microscope

Electron Microscope

Page 4: Types of microscope Electron Microscope An electron microscope

An electron microscopeAn electron microscope

Page 5: Types of microscope Electron Microscope An electron microscope

Magnification = Magnification = The number of times the image has been The number of times the image has been

enlarged by the microscope, bigger than enlarged by the microscope, bigger than the object’s real actual size. the object’s real actual size.

LM max mag. = 1,500X, EM max mag. LM max mag. = 1,500X, EM max mag. 500,000X 500,000X

Resolution (or Resolving power) =Resolution (or Resolving power) =The ability of the microscope to distinguish The ability of the microscope to distinguish

clearly between 2 points that are clearly between 2 points that are extremely close together. extremely close together.

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Figure 1.1 Magnification vs. Resolution

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ResolutionResolution The Light Microscope has a resolving The Light Microscope has a resolving

power of around 250nm power of around 250nm (nanometers) which is the same as (nanometers) which is the same as 0.250.25μμm (micrometers), so if two m (micrometers), so if two objects are closer than objects are closer than 0.250.25μμm they m they will not be detected as 2 clear points.will not be detected as 2 clear points.

The Electron Microscope has much The Electron Microscope has much better resolving power of around better resolving power of around 1nm, which is the same as 0.0011nm, which is the same as 0.001μμm, m, so it can detect much greater detail. so it can detect much greater detail.

Page 8: Types of microscope Electron Microscope An electron microscope

See my pdf notes comparing wavelenths of light See my pdf notes comparing wavelenths of light and an electron beamand an electron beam

Page 9: Types of microscope Electron Microscope An electron microscope

There are 2 different types of Electron Microscope:

Page 10: Types of microscope Electron Microscope An electron microscope

Transmission electron Transmission electron microscopemicroscope

A transmission electron microscope produces 2D images A transmission electron microscope produces 2D images from electrons from electrons which pass throughwhich pass through the sample. An the sample. An extremely thin specimen is needed.extremely thin specimen is needed.

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Golgi body Golgi body surrounded by surrounded by mitochondria mitochondria in a mouse in a mouse myeloid cellmyeloid cell

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A plant cellA plant cell

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Scanning Electron Scanning Electron MicroscopeMicroscope

A scanning electron microscope produces A scanning electron microscope produces 3D images from electrons 3D images from electrons reflected offreflected off the sample’s surface.the sample’s surface.

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Isolated Isolated mitochondria mitochondria from bovine from bovine lymphocyteslymphocytes

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Philonicus Philonicus albicepsalbiceps headhead

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This cell is a type of skin cancer cell. The cell has been frozen and split open to reveal its nucleus (central red area). (Image: Anne Weston)

Page 17: Types of microscope Electron Microscope An electron microscope

What next?What next? Complete the comparison tables on the Complete the comparison tables on the

bottom of your Handbook p4 and the top bottom of your Handbook p4 and the top of p5 booklet by circling the correct of p5 booklet by circling the correct choices and crossing out the wrong ones - choices and crossing out the wrong ones - use textbook pages 43-45 to help. use textbook pages 43-45 to help.

Now complete tasks found in the middle Now complete tasks found in the middle of handbook p5.of handbook p5.

Page 18: Types of microscope Electron Microscope An electron microscope

Units of measurementUnits of measurement 1m (1 metre) = 1000mm1m (1 metre) = 1000mm 1mm = 1000µm (micrometres)1mm = 1000µm (micrometres) 1 µm = 1000 nm (nanometres)1 µm = 1000 nm (nanometres) To convert mm to µm multiply by 1000To convert mm to µm multiply by 1000 To convert µm to mm divide by 1000To convert µm to mm divide by 1000 When doing calculations you need to When doing calculations you need to

make sure that your measurements are make sure that your measurements are in the same units.in the same units.