Nicking enzyme amplification reaction

Nicking Enzyme Amplification Reaction (NEAR) is a method for in vitro DNA amplification like the polymerase chain reaction (PCR). NEAR is isothermal, replicating DNA at a constant temperature using a polymerase (and nicking enzyme) 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.^{[1][circular reference]}

Potential advantages of NEAR over PCR are increased speed and lower energy requirements, characteristics that are shared with other isothermal amplification schemes.^[2] A major disadvantage of NEAR relative to PCR is that production of nonspecific amplification products is a common issue with isothermal amplification reactions.^[3]

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.^[4][5]