NEW YORK (GenomeWeb) – German firm GNA Biosolutions announced last week the start of a two-year collaborative project to develop its laser PCR technology into a diagnostic test for the Ebola virus.
As part of the collaboration, researchers at Mendel University in Brno, Czech Republic will also develop magnetic beads to bind the virus, and the assay will be tested at the National Institute for Infectious Diseases "Lazzaro Spallanzani," followed by field testing in Sierra Leone.
The project, called FiloDiag, will be funded with €2.3 million ($2.6 million) from the Innovative Medicines Initiative, a European pharmaceutical development funding group.
The firm hopes this project will accelerate commercialization of its laser-based PCR platform and pathogen detection cartridges, Lars Ullerich, project coordinator and co-founder of GNA Biosolutions told GenomeWeb in an interview.
The Munich-based company was founded in 2010 as a spinout from the Institute for Photonics and Optoelectronics of Ludwig-Maximilians-Universität.
The seed technology comprises "metal-based" nanoparticles that can be rapidly heated using laser light, Ullerich explained.
"They absorb laser energy extremely well, extremely efficiently; they heat up, and any double strands of DNA will melt on, or very near, that surface," he said, adding that "as soon as the laser is switched off, the nanoparticles cool down to the surrounding solution in an instant." The solution as a whole remains at a constant temperature, he said.
According to Ullerich, the method can be adapted to any qPCR protocol and the heating and cooling ramp times are "one million times faster than a conventional temperature ramp."
"For a conventional PCR you need to [thermocycle] the whole solution, in our case we just heat up the nanoparticles within the PCR samples, and they heat up and cool down almost immediately," he further explained.
Mixing the nanoparticles with sample means there is no need to worry about the limitations of small volumes, as is the case with droplet-based systems, Ullerich noted.
"We just illuminate the full sample with our laser ― in fact the laser is being scanned through the sample, and because of this we are very flexible in terms of the format of the tube or the cartridge," Ullerich said.
Developing the Ebola assay will now allow the firm to work out the details of real-time reverse-transcriptase PCR assays, he said.
In the meantime, the firm has already developed a Staphylococcus aureus qPCR assay that detects "a specific resistance gene" and has a run time of three minutes, according to Ullerich.
The firm has also developed the laser platform, which it calls Pharos400, and is now working to perfect the sample prep and the cartridge format. The on-board laser enables quantitative detection as well, but Ullerich could not provide more details at this time.
GNA Biosolutions opted to pursue intellectual property protection prior to publishing a paper describing laser PCR, Ullerich said. The firm has a portfolio of existing and pending patents covering aspects of the nanoparticle detection and different aspects of laser PCR.
It intends to have instruments ready for beta testing by the end of 2015. "Next year the assay should be ready in a very integrated format, but research-use-only tests will hopefully be available much sooner," Ullerich said. GNA Biosoultions will ultimately launch the system with either the Ebola assay, or an assay for another pathogen, he said.
In an email to GenomeWeb, Carl Wittwer, whose research also focuses on pushing the limits of PCR reaction rates, noted that a firm called Leap Medical also uses lasers for PCR heating, but that technique employs carbon nanotubes. Others in the superfast PCR arena include Rochester, NY-based Thermal Gradient, Canon US Life Sciences, and BioFire Defense, Witter also noted.
A recent study from Wittwer's own lab showed PCR speeds could be reduced further by combining small volumes, high temperatures, and primer and polymerase concentrations 10- to 20-fold higher than usual. "Our record is 35 cycles in 14.7 seconds" using this method, Wittwer said.
Meanwhile, Ullerich described Wittwer's new method as interesting, but suggested it may ultimately prove to be "academic" because the reagent concentrations required would limit diagnostic applications.
GNA Biosolutions is planning to introduce the Pharos400 platform and the first tests itself, but would be "open to strategic partnerships, especially when it comes to commercialization," said Ullerich.