Electrophoresis is a crucial step for the studies of proteins, allozymes, DNAs and RNAs. Two commonly used electrophoresis systems are agarose gel and polyacrylmide gel. Agarose gel is frequently used for DNAs and RNAs studies whereas polyacrylmide gel is widely used for the studies of other macromolecules such as proteins, allozymes (isozymes), DNAs and RNAs. The banding patterns of the gels, rather than the numbers of bands appearing on the gels are important for scoring in fingerprinting, footprinting and in population genetic studies.