Bacteriophage phi 29 DNA polymerase. The bacteriophage phi 29 DNA polymerase is involved both in the protein-primed initiation and elongation steps of viral DNA replication and displays a very processive 3’,5’-exonuclease activity acting preferentially on single-stranded DNA.
DNA Polymerase is the essential enzyme used in polymerase chain reaction (PCR). PCR is a revolutionary technique that amplifies DNA sequences, crucial for completion of the Human Genome Project and its creator, Kary B. Mullis, was awarded the Nobel Prize for Chemistry.
Alternatively phi29 DNA Polymerase (pictured above) is the replicative polymerase from the Bacillus subtilis phage phi29 (Φ29). It is being increasingly used for multiple displacement DNA amplification (MDA) procedures, a non-PCR based DNA amplification technique.
MDA can rapidly amplify minute amounts of DNA samples to a reasonable quantity for genomic analysis. Compared to conventional PCR amplification techniques, MDA generates larger sized products with a lower error frequency. This method has been actively used in whole genome amplification (WGA) and is a promising method for application to single cell genome sequencing and sequencing-based genetic studies.
DNA amplification techniques also permit early diagnosis of malignant diseases such as leukemia and lymphomas. It is also valuable in newly emerging laboratory and clinical techniques, including DNA fingerprinting, detection of bacteria or viruses (particularly AIDS), and diagnosis of genetic disorders.