Law enforcement authorities seeking to detect bioterrorism attacks, doctors diagnosing diseases, and regulatory agencies checking product safety may find a valuable new tool in detection technology developed at Lawrence Livermore National Laboratory. The lab says the technology, known as the Lawrence Livermore Microbial Detection Array, could enable law enforcement, medical professionals and others to detect within 24 hours any virus or bacteria that has been sequenced and included among the array's probes.

 

The microbial detection array detects viruses and bacteria with the use of 388,000 probes that fit in a checkerboard pattern in the middle of a one-inch wide, three-inch long glass slide. The current operational version of the array contains probes that can detect more than 2,000 viruses and about 900 bacteria, the lab says.

 

“The ability to detect the major bacterial and viral components of any sample can be used in countless different ways,” says Tom Slezak, associate program leader for Informatics at Lawrence Livermore National Laboratory. “This is important because it fills a cost-performance gap that is relevant to many missions: biodefense, public health and product safety.”

 

In the area of biodefense, current systems are centered upon the detection of smaller prioritized sets of high-risk pathogens, rather than testing for a much broader spectrum of organisms. The Livermore array can not only identify the biological pathogens on a priority screening list, but also any other already-sequenced bacteria or virus in a sample that might not have been expecting to be found, including possible novel or emerging pathogens, Slezak says.

 

The detection array will be evaluated for operational bioforensic use at the Frederick, Maryland-based National Biodefense Analysis and Countermeasures Center of the U.S. Department of Homeland Security.

 

As the cost of the array is reduced, the technology could be used to improve public health diagnostics, says Slezak, who notes that dozens of bacteria and viruses can be detected in a single test from the entire spectrum of sequenced organisms.

 

One advantage of the Livermore array is that it provides researchers with the capability of detecting pathogens over the entire range of known viruses and bacteria. Current multiplex polymerase chain reaction or PCR techniques can at most offer detection from among 50 organisms in one test.

 

Currently, Slezak's team is testing a next-generation array that boasts 2.1 million probes. This version contains probes representing about 178,000 viral sequences from some 5,700 viruses, and about 785,000 bacterial sequences from thousands of bacteria.