DNA copier uses little power

Sensors that detect DNA sequences are useful for identifying pathogens, and handheld DNA detectors would be useful for disease diagnostics, biodefense and education.

Today's laboratory DNA detectors amplify, or make many copies of a sample in order to get enough DNA to analyze. However, this replication process -- polymerase chain reaction (PCR) -- includes a heating cycle for separating DNA strands. The heating cycle requires a lot of energy.

Researchers from New England Biolabs have devised a method that copies the way DNA is replicated biologically in order to avoid the energy-intensive heating and cooling process.

The method allows the entire detection process to take place at one temperature, and could enable handheld detectors that require little power.

Biological DNA uses various molecules, including polymerases, accessory proteins and DNA helicase to carry out the replication process, with the helicase separating double-stranded DNA.

The researchers' helicase-dependent amplification (HDA) technique uses helicase to produce single strands, which are then copied using a polymerase.

The researchers are working on a lab kit that could be used in schools and are also working on an all-in-one handheld device that could be used in the field.

The method could be used practically within three years, according to the researchers. The work appeared in the August, 2004 issue of European Molecular Biology Organization (EMBO) Reports.