Nicking Enzyme Amplification Reaction (NEAR) is a method for ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

'' DNA amplification like the

polymerase chain reaction The polymerase chain reaction (PCR) is a method widely used to rapidly make millions to billions of copies (complete or partial) of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it (or a part of it) t ...

(PCR). NEAR is isothermal, replicating DNA at a constant temperature using a

polymerase A polymerase is an enzyme ( EC 2.7.7.6/7/19/48/49) that synthesizes long chains of polymers or nucleic acids. DNA polymerase and RNA polymerase are used to assemble DNA and RNA molecules, respectively, by copying a DNA template strand using base- ...

(and

nicking enzyme A nicking enzyme (or nicking endonuclease) is an enzyme that cuts one strand of a double-stranded DNA at a specific recognition nucleotide sequences known as a restriction site. Such enzymes hydrolyse (cut) only one strand of the DNA duplex, to pro ...

) to exponentially amplify the DNA at a temperature range of 55 °C to 59 °C. One disadvantage of PCR is that it consumes time uncoiling the double-stranded DNA with heat into single strands (a process called denaturation) . This leads to amplification times typically thirty minutes or more for significant production of amplified products. Potential advantages of NEAR over PCR are increased speed and lower energy requirements, characteristics that are shared with other isothermal amplification schemes. A major disadvantage of NEAR relative to PCR is that production of nonspecific amplification products is a common issue with isothermal amplification reactions. The NEAR reaction uses naturally occurring or engineered endonucleases that introduce a strand break on only one strand of a double-stranded DNA cleavage site. The ability of several of these enzymes to catalyze isothermal DNA amplification was disclosed but not claimed in the patents issued for the enzymes themselves.US Patent 6,660,475. December 9, 2003

References

* United States Patent Application 20090081670. March 26, 2009. NICKING AND EXTENSION AMPLIFICATION REACTION FOR THE EXPONENTIAL AMPLIFICATION OF NUCLEIC ACIDS. Biochemistry detection methods Genetics techniques Molecular biology {{biochem-stub