This story has been updated from a version posted Dec. 16 to include additional information from company officials.
Rheonix last week introduced its Hy-Fi microarray platform for biomarker discovery and clinical diagnostics.
John Brenner, the firm's vice president of IP management and licensing, told BioArray News that the Hy-Fi array platform enables multiplexed end-point detection for molecular assays, especially SNP detection.
Additionally, Brenner said that the platform has a "strong future" in the clinic, particularly in companion diagnostics, where it can potentially be used to analyze "particular genetic SNPs associated with pharmacogenomics." According to Brenner, Rheonix has ongoing test-development programs to use variations of its array platform in pharmacogenomics, oncology, and infectious diseases.
Rheonix began in 2003 as a research group within Kionix, an Ithaca, NY-based manufacturer of accelerometers, gyroscopes, and microfluidics. The privately held firm became independent from Kionix in 2008 and remained in Ithaca.
Since that time, Rheonix has launched multiple "chemistry and reagent devices," or CARDs, for use on its benchtop instrument, EncompassMDx. These CARD cartridges offer "fully integrated" assays, "from raw collected biological sample through to an analytical endpoint without operator intervention after starting the assay," and are able to process biological samples from 5 microliters to 3 milliliters.
To date Rheonix has developed CARD assays for a number of applications including immunochemistry, environmental biology, food safety, and molecular biology. Brenner said that the most well-developed assays are in the area of molecular biology and use the Hy-Fi microarray platform as an endpoint analytical tool.
"Most of the assays that are under development are non-quantitative multiplex assays," Brenner said. "Therefore a simple, reliable endpoint tool was needed, so we developed the Hy-Fi microarray. In particular, we are developing assays for certain [SNP] studies where the fidelity of the hybridization is critical to the success of the assay."
Hy-Fi uses Exiqon's locked nucleic acid chemistry for SNP analysis. LNAs are a class of high-affinity RNA analogs in which the ribose ring is locked in the ideal conformation for Watson-Crick binding, thus exhibiting "unprecedented thermal stability when hybridized to a complementary DNA or RNA strand," according to Exiqon's website.
Vedbaek, Denmark-based Exiqon has licensed its LNA technology to a number of other firms, including Integrated DNA Technologies, Idexx Laboratories, and Becton Dickinson. The company relies on the technology to produce its own menu of microRNA microarrays.
Rheonix claimed in a statement that LNAs "improve the fidelity of the base pairing to exclude non-specific base pair hybridization," as well as "provide a high signal-to-noise ratio, making the microarray's results easier to interpret."
Brenner said that "selectively interspersing" the LNAs when manufacturing the firm's SNP microarrays helps avoid non-specific hybridization. He added that Rheonix has developed a tool to print DNA, RNA, and protein microarrays with "superior spot quality and outstanding reproducibility" between arrays.
"In general, low-density microarrays suffer non-uniform morphology of spots within and between microarrays," said Brenner. "Spots often look either like fried eggs or like coffee rings when the spots dry unevenly as they are produced," he said. This variance introduces challenges when comparing the array’s post-hybridization results, causing false or misleading data.
He said that Rheonix's spotter "reliably produces uniform spots that avoid such variability" in a single pass.
While Rheonix has initially configured the system for its own "high-volume" microarray fabrication, it said in a statement that it can produce custom arrays using the same processes, fabricating for partners low-density DNA, RNA, and protein arrays for use in research and clinical applications.
"Our platform is adaptable to a wide variety of sample sizes and types," said Brenner.
Rheonix currently has its own CARDs in development for human papillomavirus testing, warfarin sensitivity testing, sepsis detection, sexually transmitted disease testing, and drinking water screening. Though none of these CARDs have achieved US Food and Drug Administration clearance for clinical use, Brenner said that Rheonix is preparing to proceed with a clinical trial under the FDA's 510(k) protocol for a warfarin sensitivity test and intends to follow that clinical trial "shortly thereafter" with a trial for its CYP2C19 SNP analysis CARD.
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