Checking DNA fragments.

Gel Electrophoresis Gel electrophoresis separates macromolecules on the basis of their rate of movement through a gel under the influence of an electric field. As the diagram indicates, mixtures of nucleic acids are placed in wells near one end of a thin slab of a polymeric gel. The gel is supported by glass plates and bathed in an aqueous solution. Electrodes are attached to both ends, and voltage is applied.  Since the nucleic acids are negatively charged, due to the negatively charged phosphate group, they will migrate to the positively charged electrode. However, their rate of movement differs, as they have different sizes. The rate of movement is inversely proportional to the size of molecules. That is, large molecules move slower that small molecules.  This technique is used to identify and separate DNA fragments that are cut by restriction enzymes.

 

Relating Topics
- Sanger Method