Gel electrophoresis is a technique for separating DNA, protein or RNA fragments based on the size and charge.
By applying electricity, different size of fragments will move in the gel with different speed. The larger will move slowly and concentrate at the top while the smaller will move faster and concentrate at the bottom.
With the presence of the molecular weight ladder as a reference, we can estimate the size of the fragments.
Below we introduce the procedure of running gel electrophoresis.
(1) Obtain the DNA sample from DNA extraction or Polymerase Chain Reaction (PCR)
(2) Get a little amount of DNA sample mixed with loading dye for visible banding in gel electrophoresis.
(3) Prepare an agarose gel. Add a little amount of gel stain to agarose solution. Pour the mixed solution to a mould for solidification.
(4) Transfer the gel to an electrophoresis tank. Be careful of making any gas bubble.
(5) Put the molecular weight ladder and samples mixed with the DNA dye accordingly from left to right.
(6) Apply electricity and bandings should be observed under UV light.
Basic Knowledge(1): DNA Structure and Nucleotide
Basic Knowledge(2): DNA Replication
Biotechnology(1): DNA Extraction
Biotechnology (3): Polymerase Chain Reaction
Species Identification