Proteins and DNA in systematic biology.

Since the 1960s, biological macromolecules have occupied an increasingly important role in evolutionary and systematic studies. These biological macromolecules, used as sources of molecular characteristics, are proteins and various types of DNA such as a nuclear genome, nuclear ribosomal DNA, mitochondrial genome, and chloroplast genome. Electrophoresis and immunological techniques are used for generating systematic data from proteins. Generally, electrophoretic methods focus on two general forms of protein data, isozymes and allozymes, while the basis of immunological studies is antigen-antibody reactions. Basic methodologies for using DNA for systematic purposes include DNA-DNA hybridizations, restriction enzyme analysis, sequencing, cloning, PCR and PCR-based fingerprinting techniques.