NEW YORK (GenomeWeb) – Nucleic acid testing firm Thermal Gradient has moved into the prototype testing phase for the core component of its three planned instruments.
Called FlashAmp, FlashDirect-LC, and FlashDirect-HC, the systems are are all extremely small-footprint qPCR platforms with multi-channel fluorescence detection and thermal melt capabilities, and each has characteristics that make them ideal for specific sample types and end applications.
The mechanical design of the systems was created internally, Thermal Gradient CEO Robert Juncosa told GenomeWeb in an interview. The electronics were contracted out to a firm in Syracuse, the optics were produced by Semrock in Rochester, New York, and the enclosure was created using stereolithography, or SLA printing.
"Now what we're doing is integrating everything and making some adjustments to the software," Juncosa said, adding that the core of the system had previously been in a form with different pieces, "but this is the first time it has all been integrated into a product-like system."
FlashAmp, FlashDirect-LC, and FlashDirect-HC are "almost identical from an instrument standpoint, only the cartridge is different," Juncosa explained. They all use inexpensive, disposable cartridges, with run times between two and eight minutes for a 40-cycle qPCR.
The FlashAmp is a research-use platform for the non-diagnostic market that requires separate sample preparation. There are also two sample-to-answer instruments: The FlashDirect-LC for low-complexity samples, like throat and nasal swabs or saliva, and the FlashDirect-HC for higher-complexity samples, such as serum and plasma.
The enabling thermal cycling and nucleic acid extraction technologies are proprietary. However, Juncosa told GenomeWeb the firm uses a 3D approach to PCR to shorten the thermal transition times, with areas in the core device maintaining different temperatures and made of different materials.
Specifically, the device is folded, with a front, middle, and back layer each having different thermal conductivities. The system may ultimately be less expensive to run because the input energy is only used to maintain different temperature zones, rather than to cycle between temperatures.
This core structure can handle continuous flow as well as reciprocating PCR, in which the sample shuttles back and forth. "The reciprocating PCR gives us more flexibility in terms of how many cycles and the protocol itself, and it helps make it easier for us to do quantitative tests," said Juncosa.
This spatial thermal cycling method has similarities with the Roche Liat point-of-care system, which is based on technology acquired from Iquum, "But geometrically, it's very different because ours is three dimensional, and relies on the different thermal properties of the different layers" noted Juncosa.
The method is efficient enough that the system can be more "minifludics" than microfludics, which is an advantage since "for most diagnostic purposes, you need higher sample volumes," Juncosa said.
The FlashAmp is "basically a superfast single-channel PCR thermal cycler, much like the SmartCycler from Cepheid or the LightCycler from Roche," Juncosa explained, adding that this system would perform a low number of tests per run but also does not require clearance by the US Food and Drug Administration for its intended applications. It performs qPCR as well as thermal melt.
The differentiating feature between the LC and HC systems is the sample prep.
The FlashDirect-LC is meant for "swabs, urine, [or] saliva — things that aren't as complex and don't have as many inhibitors." Thermal Gradient is targeting this platform for hospital-acquired infections, such as methicillin-resistant Staphylococcus aureus, as well as biodefense and forensics applications. The FlashDirect-HC, meanwhile, is meant for blood-based testing, for pathogens like HIV and malaria.
The cost of the instruments is likely to be low. However, the final price will depend on what path the firm takes to commercialization. The most likely scenario, based on ongoing conversations Thermal Gradient is having with potential partners, is that the technology will be commercialized by another firm, Juncosa said.
The energy efficiency and simplicity of the core apparatus suggest these platforms will be "far less expensive than other instruments," Juncosa said. Previous versions of the device were silicon, or injection-molded metal and plastic, but the current version is all plastic, which has driven the cost of the cartridge down to the tens of cents range.
Potential partnerships will shape regulatory strategies as well. Juncosa said Thermal Gradient intends to seek FDA clearance on its own for the two diagnostic platforms, but he sees it as more likely that a partnering or acquiring company will take over and implement its own regulatory plans.
"We may be interrupted even before we get the FlashAmp on the market," he said.
FlashAmp's release may also depend on external interest, but Juncosa said it will be sometime at the end of this year or the beginning of next year.
Thermal Gradient began the development process for its platforms about five years ago, as previously reported by GenomeWeb.
Previously based in Rochester, New York, the company moved its five-person team to the Virginia Biotechnology Research Park in Richmond, Virginia last year. It has since hired two more staff members, and plans to hire several more.
Although there are now a number of players in the point-of-care diagnostics market, Juncosa claimed that Thermal Gradient is "the answer to point-of-care." In his opinion, other firms are trying to adapt non-point-of-care approaches to point-of-care, squeezing the cost out of all components, "and it is difficult." The Thermal Gradient technology, on the other hand, is inherently small and simple.
He also noted that the core device can be used on a larger scale.
"We think we're the only company that can truly bring random-access, high-throughput nucleic acid analysis to reference lab equipment," Juncosa said, adding that platforms like the Roche Cobas, Abbott m2000, or Beckman-Coulter DxN Veris would be "far better served if they had Thermal Gradient [technology] inside."