By Ben Butkus
Lynntech, a Texas-based technology-development firm specializing in energy, water, and health innovations, is developing a simplified magnetic particle-based nucleic acid sample prep module intended for use prior to molecular diagnostic assays in resource-poor areas of the world, the company recently disclosed.
In addition, Lynntech is working with various academic institutions and technology-commercialization groups to develop a point-of-care, PCR-based molecular testing platform that features a new and proprietary thermal cycling method, and is also intended for use in non-traditional healthcare settings, Season Wong, a Lynntech senior scientist heading both projects, told PCR Insider this week.
Both projects are in the very early stages, however, and the group is "open to collaboration with other commercial entities," Wong said.
Wong presented his group's work on the sample prep module earlier this month at the Knowledge Foundation's Integrating Sample Preparation conference in Washington, DC, and discussed the project with PCR Insider in an interview following the conference.
Wong noted that although molecular diagnostic testing in many cases has become the gold standard for infectious disease testing, most assays are run at centralized locations on highly automated systems that require samples to be batched, thus delaying time to result and potential treatment for patients in lower-resource locations.
To address this issue, Wong and colleagues, with the support of various government grants, have devised a portable, low-cost module that can extract DNA and RNA from a variety of clinical samples and potentially be coupled to any existing downstream detection platform.
The module uses proven magnetic particle-based nucleic acid purification. However, instead of traditional protocols, which require several steps and can potentially expose users to infectious agents or expose samples to environmental contaminants, Lynntech's prototype is a closed system that can accommodate pre-loaded reagents and can be run via battery power or manually, depending on the situation and setting.
The technology accomplishes this by using a so-called magnetic-assisted plug valve system that incubates magnetic particles in a lysed sample and transports them between several approximately 300-µL chambers through the sequential use of magnetic capture, 180-degree valve rotation, and magnetic particle re-suspension.
"The idea is a very low-cost approach that can be used in a very low-resource setting, away from a central lab or clinic, even in the field," Wong said. "The device is very simple, a piece of plastic, that can be operated manually, or hooked up to a low-cost actuation device that will carry out the extraction procedure."
Wong also noted that the "magnetic particle extraction chemistry is already there. We are not reinventing the chemistry, although we can potentially add some proprietary chemistry that optimizes the extraction protocol."
So far the group has conducted internal proof-of-concept studies of its sample prep module, using it to isolate and purify DNA from whole blood samples; rapidly extract DNA from human buccal cell swabs; and conduct PCR detection of pathogenic DNA from swabs. In all cases, endpoint and real-time PCR confirmed that the module yielded high-quality extracted nucleic acid.
The group also conducted downstream real-time PCR amplification of DNA extracted from Bacillus subtilis-spiked whole human blood using both their sample prep module and Qiagen's QIAcube sample prep device, and achieved similar results using both.
Wong's group also recently received a $200,000 Phase I Small Business Innovation Research grant from the National Institute of Allergy and Infectious Diseases to support the development of a rapid, easy-to-use, inexpensive molecular diagnostic system, primarily for use in the developing world.
Although the grant specifically supports development of a platform for diagnosing sexually transmitted diseases such as chlamydia and gonorrhea, Wong said that it could be used for multiple infectious agents; and may even be adapted for applications such as biodefense or environmental testing.
In Phase I of the project, the group will develop a low-cost thermal gradient cycler that will be able to perform rapid PCR for CT/NG targets. This thermal cycler design will feature a "simplified architecture" that creates a stable thermal gradient from a single heat source, the grant's abstract states.
This will be coupled with a lateral flow strip component incorporated in a 0.2-mL PCR tube for detecting PCR amplicons. This integration, the grant's abstract states, allows the amplification and detection to be performed in a closed system, eliminating post-PCR contamination concerns, and permitting users with minimal technical training to read and interpret results.
According to Lynntech, the entire assay will be able to be completed in less than 45 minutes, including sample preparation. The thermal gradient cycler can be built with less than $100 worth of parts; and the lateral flow detection device should cost no more than $2 to manufacture, according to the grant's abstract.
Lynntech is carrying out the proposed work in collaboration with various academic researchers, including Charlotte Gaydos, from Johns Hopkins University, who will contribute STD expertise; GuoDong Liu, from North Dakota State University (nanomaterials and lateral flow assay development); Victor Ugaz from Texas A&M University (fluidic/thermal characterization); and Yi-Wei Tang, from Vanderbilt University (clinical sample preparation). Lynntech will also work with Diagnostic Consulting Network, a contract assay development firm that will assist with technology commercialization and provide consultation in the area of lateral flow assay design and manufacturing.
"With this grant, we again would like to aim for a low-resource setting," Wong said. Specifically, "for the STD [assays], we are hoping they can be used away from the laboratory. Sometimes … it's really hard to get people to go see a doctor, especially when they are not that wealthy or don't have insurance. And even when people can pay they sometimes just don't go back to the doctor get a result from a test. There are no return visits from some of these patients."
While Lynntech's sample-prep module could be eventually integrated with its point-of-care testing platform, the two technologies are being developed independently, Wong said. As such, the sample-prep module could be used in front of a variety of commercial molecular testing methods; while the molecular testing platform could use different types of sample-prep technologies.
"The sample prep is not covered in the grant," he said. "It could be integrated into the platform, but it could be that we decide that some other technology actually works better than what we can do."
Moving forward, Wong's group hopes to further develop and validate both technologies, possibly in collaboration with other commercial entities. Wong noted that he was heartened by the positive response to his presentation at the Knowledge Foundation Sample Prep meeting.
"All the proof-of-concept data we presented has given us a strong indication that the technology is viable," he said. "Based on audience response, people understand the concept and it won't be difficult to take it a step further."
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