Chapter 2.1 Slides, photo -micrographs and measuring
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- Created on: 22-05-16 12:54
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- Chapter 2.1 Slides, photo -micrographs and measuring
- Observing unstained specimens: Some microscopes use light interference, rather than light absorption to produce a clear image without staining .
- Some use a dark background against an illuminated specimen so it shows up.
- Staining specimens: Stains are coloured chemicals that bind to molecules on or on the specimen, making the specimen easy to see Methylene blue is an all-purpose stain.
- Observing prepared specimens: Experts in a labatory by: Dehydrating the specimens or embedding them in wax to prevent distortion during slicing.
- How to work out calculations involving magnification: Convert mm to um by multiplying by 1000 -divide the figure by the magnification.
- Formula: M=I/A or A=I/M or I=AxM A=actual size I=image size on micrograph M=magnification.
- Using graticules: A graticule is a transparent with a ruler which is fitted onto a microscope -the scale represents different lengths at different magnifications
- A stage graticule is used to calibrate the graticule. it is 1mm long and divided into 100 division
- Observing unstained specimens: Some microscopes use light interference, rather than light absorption to produce a clear image without staining .
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