Gene amplification

Gene amplification refers to a number of natural and artificial processes by which the number of copies of a gene is increased "without a proportional increase in other genes".^[1]

Artificial DNA amplification for research or diagnosis can be conducted through methods including:

• Polymerase chain reaction, an easy, cheap, and reliable way to repeatedly replicate a focused segment of DNA by polymerizing nucleotides, a concept which is applicable to numerous fields in modern biology and related sciences.^[2]
• Ligase chain reaction, a method that amplifies the nucleic acid used as the probe. For each of the two DNA strands, two partial probes are ligated to form the actual one; thus, LCR uses two enzymes: a DNA polymerase (used for initial template amplification and then inactivated) and a thermostable DNA ligase.^[3]
• Transcription-mediated amplification, an isothermal, single-tube nucleic acid amplification system utilizing two enzymes, RNA polymerase and reverse transcriptase, to rapidly amplify the target RNA/DNA, enabling the simultaneous detection of multiple pathogenic organisms in a single tube.

In natural DNA replication, a natural form of copying DNA, gene amplification can occur through gene duplication, a major mechanism through which new genetic material is generated during molecular evolution. Common sources of gene duplications include ectopic recombination, retrotransposition event, aneuploidy, polyploidy, and replication slippage.^[4]

A piece of DNA or RNA that is the source and/or product of either natural or artificial amplification or replication events is called an amplicon.^[5]

References