DNA and protein identification in the same device?

Applied Biosystems (ABI) has signed an agreement with US company Eagle Research and Development to collaborate on further developing a single molecule detection device invented by Eagle.

As part of the agreement, Applied Biosystems has received an exclusive two-year option to license the technology.

Eagle's patented technology, currently in prototype stage, identifies and quantifies molecules based on their unique electronic charge signatures.

A spokesperson for ABI said the company believed the technology could have significant implications for advancing personalised medicine based on its potential for faster, more efficient and less expensive protein and nucleic acid identification, protein-protein and protein/small molecule interaction measurements, and DNA sequencing.

ABI intends to focus initial development support and feasibility testing for applications in protein identification and detection of protein-binding events. Provided the ability to electronically profile the individual four nucleotides in DNA is further developed, the company said it believed the Eagle technology could potentially be the first to enable the identification and measurement of both DNA and proteins in a single sample at the same time.

Eagle received a two-year research grant from the US National Human Genome Research Institute in 2002 to demonstrate a unique DNA detection method using a nanopore-based device. Nanopores are extremely small openings in a thin membrane or silicon chip. When an electronic voltage is applied, molecules pass through these pores enabling each unique molecular component to be identified and counted.

The miniature silicon device constructed by Eagle consists of an array of nanopores, with each nanopore containing embedded semiconductors or field-effect transistors (FETs). As single molecules are driven through a nanopore by a voltage differential, the three-dimensional charge profile of a molecule is measured by the FETs, enabling each molecule in the sample to be uniquely identified and precisely quantified.

Jon Sauer, founder of Eagle Research and Development, said the technology offered the prospect to eventually correlate DNA and its expressed proteins with specific disease states using a disposable and portable device.

"For example, the device has the potential to enable development of exquisitely targeted treatments using sequencing data both from a patient and from the disease-causing pathogen," he said.

The Eagle device is unique because it measures a molecule's three-dimensional electronic charge profile directly, as opposed to measuring electronic current or conductance. Further, it does so without the use of fluorescent or other labels, thermal cycling or optics.

Nanopore technology is one of several next-generation life science research platforms in which Applied Biosystems is investing. In July this year, ABI acquired Agencourt Personal Genomics for its sequencing by stepwise ligation technology (see "The next generation in sequencing is SOLID", Australian Life Scientist, Jul/Aug 2006). In December 2005, it made an investment in VisiGen Biotechnologies for its real-time single-molecule sequencing technology.