Luminex is developing an automated, handheld, battery-powered diagnostic system based on its xMAP technology to administer both molecular and immunoassays to help diagnose soldiers or provide biosurveillance data at the point of need, the company said this week.
Although Luminex in August disclosed the project — which is being funded over the next three years with up to $11.6 million from the Defense Threat Reduction Agency of the US Department of Defense — company officials shared more details this week, including the fact that system will be enabled by digital microfluidics technology from partner Advanced Liquid Logic.
In addition, even though Luminex is developing the system primarily for biodefense-related purposes, it could eventually find use in other applied markets, such as food safety testing, and even in clinical diagnostics — but much further down the road.
"The contract we received from [DTRA] is a development contract," Amy Altman, vice president of biodefense at Luminex, told PCR Insider. "The technology we're developing under this contract is pretty new, very flexible, innovative, and there is some risk associated with it, so it's still very much in the development phases. Obviously we like to get things funded that will align with our corporate business … [and] this is a fairly long contract, a development contract, with the hope that we can eventually apply some of those things to our commercial business."
A Luminex scientist discussed the technology, and specifically the sample prep aspects of it, in a presentation at the Knowledge Foundation's Sample Prep conference last week in San Diego. PCR Insider did not attend the conference, but interviewed Altman regarding the technology ahead of time.
Altman said that the project spawned from the US military's desire to have more "field-forward diagnostics" at its disposal.
"The [DoD] is concerned about not only infectious diseases in terms of [identifying] the pathogen — and there are a lot of technologies out there, such as PCR technologies, for that — but also what happens when you have sepsis or a sepsis-like illness, with all these inflammation markers, which are protein biomarkers. How does that correlate with a soldier's outcome or health when they have a traumatic injury, or an infectious disease that's endemic to a region where they're deployed?"
Altman said that the major differentiating feature of its platform will be its ability to perform both a molecular assay and an immunoassay from the same sample on the same disposable test cartridge. Few, if any, commercial platforms have such a capability, although other companies, such as Spain's Stat-Diagnostica, are working on similar technologies (see related story, this issue).
"There are a lot of people doing PCR, and a lot doing cartridge-based PCR systems — obviously our Aries system is more of a real-time cartridge-based sample-to-answer system," Altman said, referring to Project Aries, Luminex's benchtop, sample-to-answer molecular testing system currently under development (PCR Insider, 5/2/2013 and 12/13/2012).
But while that platform is using MultiCode PCR chemistry that Luminex acquired along with EraGen in 2011, the field-based system will essentially be a miniaturized version of Luminex's xMAP and xTAG technologies, which is currently featured in its Luminex 100/200 and Magpix systems for highly multiplexed clinical infectious disease tests such as the company's Gastrointenstinal Pathogen Panel or Respiratory Virus Panel.
In a Luminex xTAG assay, PCR products undergo an allele-specific primer extension step. The 5' end of the primers are then attached to an xTAG universal tag sequence that is hybridized to the complementary anti-tag sequence coupled to xMAP beads, which are subsequently read and analyzed on the Luminex 100/200 and Magpix.
The portable system being developed under the DTRA grant will be 'sample-to-answer and cartridge-based, but based on digital microfluidics," Altman said. "We have a collaborator in this effort — Advanced Liquid Logic, which has electrowetting technology. The system is based on that technology in which we can take a sample and test for both an infectious disease agent, say, anthrax or malaria, or any bug in our GPP or RVP targets; and we can also look for markers of inflammation within a soldier. There are a number of protein markers that increase when you have an inflammation or some kind of traumatic event within the body, and those are often prognostic … and can inform care."
Having begun in 2010, Luminex's partnership with Morrisville, NC-based ALL pre-dates the DTRA contract, but was established with a portable IVD system in mind. ALL's electrowetting technology uses electric fields to move nanodroplets, enabling liquid handling without pipes, pumps, or valves.
This technology, Altman said, enables Luminex to take a unique approach to PCR amplification.
"When you're dealing with a digital microfluidic-type platform, the volumes are very small, so your thermal cycling can be extremely rapid, [and] you can move your droplet over different temperature zones," Altman said. "Traditional PCR is typically one to three hours depending on the level of detection you need. We can reduce that greatly and get answers in under an hour, maybe under a half hour."
This timeframe aligns well with immunoassays, which typically provide results much faster than PCR-based assays.
Another potential advantage of ALL's technology is the ability to concentrate a target down, "giving you the real estate to do multiple things at once," Altman said. "Essentially you have this … printed circuit board where you move your droplets around through electrowetting, so you can process many things simultaneously."
Altman said that it was too early to disclose the particular infectious disease targets that Luminex plans to tackle on the system, but noted that the contract is focused on "biowarfare pathogens as infectious agents … and markers of systemic inflammatory response."
The goal at the end of the DTRA contract would be to have a functional system that the US military could then potentially acquire for deployment. "That's not really a directive of the contract though, it's a development contract."
And even if Luminex will not necessarily adapt the system for its own commercial clinical diagnostics use in the near future, it might be useful for other applied markets, such as food testing.
"I'm actually VP of biodefense and food safety," Altman said. "Pretty much anything in the specialty markets falls to me. We're not doing a whole lot in food safety right now, although we have a few products. But our assays in the food space overlap a lot with biodefense."