Gel electrophoresis Flashcards
What is the basis of gel electrophoresis?
Sections of DNA of different sizes are separated.
How is this allowed to happen?
A small current in a buffer solution flows through an agarose gel from the cathode to the anode, Connected to a power pack at the negative end.
Why do fragments travel different lengths?
Travel at different speeds and different distances depending on their size (the size of their charge) as DNA is negatively charged due to the presence of a phosphate. The smaller the fragment the further the distance.
How are the wells made in the agarose gel?
Wells are sunk into different points along the cathode. A ‘comb’ is placed in-situ when the gel is molten and removed once it hardens.
How is the DNA cut into different sized fragments?
Different restrictions enzymes are placed into each well.
How are the bands detected?
Using either methylene blue or UV light.
What are the controlled variables?
Run time and voltage.
