Electrophoresis
Electrophoresis Mind Map
- Created by: Elizabeth Hampson
- Created on: 19-03-13 11:24
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- Electrophoresis separates DNA fragments
- Based on size, can separate fragments different by only one base in length.
- Gel slab contains agarose + buffer solution. Electrodes attached to each end so a current can be passed through.
- Separation of strands of different lengths occurs because longer stands get caught in the agarose gell and are slowed, but shorter strands can move more quickly.
- Basic Procedure
- 1. DNA samples treated with restriction enzymes
- 2. Placed into wells cut into -ve electrode end of gel
- 3. Electric current passed through for fixed time
- 4. DNA attracted to +ve electrode (diffuse)
- 5. Dye stains DNA
- 4. DNA attracted to +ve electrode (diffuse)
- 3. Electric current passed through for fixed time
- 2. Placed into wells cut into -ve electrode end of gel
- 1. DNA samples treated with restriction enzymes
- Fragments lifted from gel for further analysis.
- Southern Blotting: nyon or nitrocllulose sheet placed over gel,
- DNA can be labelled with a radioactive marker before the samples are run. Placing photographic film over the nitrocellulose sheet shows positions
- A DNA probe is a short single strand of DNA (50-80 nucleotides long) complementary to specific section of DNA
- Radioactive marker - detected by exposure to photographic film
- Annealing - binding by complementary base pairing
- Flourescent marker - detected by UV light
- Locate gene for genetic engineering
- Genome comparison
- Genetic disease diagnosis
- Probes placed on a fixed surface - DNA microarray
- Amplified using PCR
- Annealing - binding by complementary base pairing
- Flourescent marker - detected by UV light
- Radioactive marker - detected by exposure to photographic film
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