Helicase-dependent amplification

Helicase-dependent amplification (HDA) is a method for in vitro DNA amplification like the polymerase chain reaction (PCR).

The disadvantage of PCR is that it consumes a lot of time with uncoiling the double-stranded DNA with heat into single strands (a process called denaturation) and copying the single strands to create new double-stranded DNA (synthesis). Instead of these thermocycles, HDA mimics nature’s method of replicating DNA by using helicase (an enzyme) to denature the DNA at a constant temperature of 37°C.

The advantages of HDA over PCR are increased speed, reduced costs and the prospect of creating a hand-held DNA diagnostic device. The disadvantage is that HDA still requires a relatively large amount of DNA, so it presumably will not be used in cases where high sensitivity is needed.

External references

 * "Helicase-dependent isothermal DNA amplification"Myriam Vincent, Yan Xu & Huimin Kong EMBO reports AOP
 * "DNA duplication trick may lead to faster testing", New Scientist, July 9, 2004
 * "A Better Way to Copy DNA", Newswise, July 9, 2004