Cancers tend to produce microRNA molecules that are present in whole blood and, if isolated and sequenced, can serve as excellent biomarkers for the presence of cancer. Researchers at Nagoya University in Japan have come up with a device that can rapidly separate microRNAs from a mixture of RNA and DNA, opening the door for microRNAs to become a practical biomarker for cancer, and potentially a variety of other diseases. Coupled with nanopore sequencers, which operate at high speed, a complete microRNA biomarker identification system is not far off.
The new technology demonstrated the ability to completely filter out microRNAs from a sample within 100 milliseconds, a record time for any technology. It relies on a layer of quartz that has matrix of tiny columns, each only 250 nanometer in diameter, that sit within narrow slits.
The nanobiodevice consists of a quartz substrate containing a 25×100 μm array of “nanopillars” (small columns with a diameter of 250 nm and height of 100 nm) in shallow “nanoslits” with a height of 100 nm and fabricated in a microchannel by electron beam lithography.
“We believe that the nanobiodevice separates microRNA from mixtures through a combination of two different physical behaviors of confined polymers in the nanopoillar array, non-equilibrium transport and entropic trapping,” said one of the study authors, Noritada Kaji, in a statement. “The applied electric field combines with the unique nanostructure of the nanobiodevice to generate a strong electric force that induces rapid concentration and separation.”
Study in Scientific Reports: A millisecond micro-RNA separation technique by a hybrid structure of nanopillars and nanoslits…
