Following the anthrax attacks in late 2001, The Defense Advanced Research Projects Agency (DARPA) contracted with U.S. Genomics (USG) to better understand how single molecule DNA mapping technology could be applied to the detection of biological threats.  This work indicated that the USG approach had the potential to detect dangerous pathogens with extremely high sensitivity (>99%) and accuracy (false positive rate of 1 in 10,000,000 tests). It also indicated that unlike conventional approaches, which require a specific set of reagents for each biological threat to be detected, USG's approach facilitates the use of a single reagent set to detect a large number of biological threats.

Following completion of the DARPA contract in mid-2003, USG was selected by the Homeland Security Advanced Research Projects Agency (HSARPA) from more than 500 submissions to develop a specialized biosensor for detection of pathogens in the air.  Since 2003, USG has received more than $37 million in contract funding for this device, termed a Bioagent Autonomous Networked Detector (BAND).

How USG Biosensing Technology  Works

The uniqueness of all living organisms is derived from the DNA sequence of their individual genomes.  Sequencing technologies that can determine the specific A, T, C, G code of an organism are very slow, expensive and cumbersome, taking months or even years for a single genome to be sequenced.  USG's single molecule DNA mapping technology enables low resolution snap-shots of DNA to be taken at a speed of hundreds of genomes per second.  USG's approach does not yield the specific sequence of the target DNA - but instead reveals a unique pattern from each piece of DNA in a sample that is based on the underlying genomic sequence.  These patterns, represented by barcodes, are an exceptionally accurate method for determining whether any individual DNA molecule in a sample resembles the DNA that could be expected from a specific biological threat.

USG Pathogen Detection Process

The application of USG's approach to detection of pathogens has four basic steps as illustrated above: (1) DNA is extracted from the organisms in an air or other biological sample using a proprietary technique; (2) a fluorescent label that binds to a specific short frequently occurring DNA  sequence is added to the sample; (3) the fluorescently labeled sample DNA is stretched in a microfluidic chip and subjected to laser interrogation, revealing a pattern that is unique to each piece of sample DNA; (4) the pattern or barcode from each piece of sample DNA is compared to a database to determine whether they may have come from a specific pathogen.  In the case of the HSARPA BAND program, the sample is extracted from air.  The process is fully automated and takes just a few hours from sample to answer.

More Flexible and Accurate than Competing Technologies

Most current methods of biological threat detection are based on a laboratory technique called amplification.  Under this technique, a special set of reagents causes genetic material that is unique to a specific pathogen to make exponentially more copies of itself such that in a short period of time (~60 minutes) there are hundreds of billions of copies of the genetic material - enough to be seen with a conventional imaging device.  This approach, more than three decades old, has certain well known and characterized shortcomings.  First, a specific set of reagents must be used for each different biological threat, making it cumbersome and expensive to search for a large number of threats.  Second, amplification sometimes makes copies of the wrong target.  When this occurs the error is amplified leading to a false positive.  Third, certain environmental contaminants, such as diesel soot, can prevent amplification from taking place, masking presence of a real threat.  And fourth, prevalence and knowledge of the technique make it vulnerable to defeat through genetic modification of pathogens to prevent amplification.

The Department of Homeland Security's current biological threat detection network, Biowatch, utilizes detection technology based on amplification.  The network is very expensive to operate and is only capable of detecting a small number of biological threats.  USG's approach does not use amplification, can detect a large number of threats (100's) with a single reagent set, is more sensitive and accurate, is more difficult to defeat, and can be less expensive than conventional approaches. These factors provide tactical benefits by enabling a larger, more effective network to be deployed and strategic advantages through flexibility to detect a broader range of biological threats, including genetically modified and emerging threats which existing approaches have difficulty detecting.

Partnered with Market Leader for Biosensor Commercialization

USG is partnered with Northrop Grumman Corporation for commercialization of the biosensor for homeland defense.  Northrop Grumman is the market leader in deployment and operation of biosensors for the U.S. Government, and is responsible for installation and operation of the extensive surveillance system currently deployed at the USPS.