DNA replicationis the process of producing two identical replicas from one originalDNAmolecule. This biological process occurs in allliving organismsand is the basis forbiological inheritance. DNA is made up of two strands and each strand of the original DNA molecule serves as template for the production of the complementary strand, a process referred to assemiconservative replication. Cellularproofreadingand error-checking mechanisms ensure near perfect fidelity for DNA replication.
In acell, DNA replication begins at specific locations, ororigins of replication, in thegenome.[3]Unwinding of DNA at the origin and synthesis of new strands results inreplication forksgrowing bidirectionally from the origin. A number ofproteinsare associated with the replication fork which helps in terms of the initiation and continuation of DNA synthesis. Most prominently,DNA polymerasesynthesizes the new DNA by adding complementarynucleotidesto the template strand.
DNA replication can also be performedin vitro(artificially, outside a cell). DNA polymerases isolated from cells and artificial DNA primers can be used to initiate DNA synthesis at known sequences in a template DNA molecule. Thepolymerase chain reaction(PCR), a common laboratory technique, cyclically applies such artificial synthesis to amplify a specific target DNA fragment from a pool of DNA.
