A new technology detects disease biomarkers in the form of nucleic acids, which are the molecules that comprise DNA and RNA.1
“We envision this as a potential first-line, noninvasive diagnostic to detect anything from cancer to the Ebola virus,” said Adam R. Hall, PhD, assistant professor of biomedical engineering at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina, and lead author of the study. “Although we are certainly at the early stages of the technology, eventually we could perform the test using a few drops of blood from a simple finger prick.”
The test is zeroing in on microRNA, or sequences of RNA that are only approximately 20 bases long. MicroRNAs can signal a wide range of diseases, including cancer.
“Scientists have studied microRNA biomarkers for years, but one problem has been accurate detection because they are so short, many technologies have real difficulty identifying them,” Hall explained.
This new technique uses nanotechnology to determine if a specific target nucleic acid sequence exists within a mixture. If it does, then it is quantified through a simple electronic signature.
“If the sequence you are looking for is there, it forms a double helix with a probe we provide and you see a clear signal. If the sequence isn’t there, then there isn’t any signal,” Hall said. “By simply counting the number of signals, you can determine how much of the target is around.”
The first step in this study was to demonstrate that this technology could effectively identify a specific sequence among a background of competing nucleic acids. Next, this approach was applied to mi-R155, which is a particular microRNA known to indicate lung cancer in humans. The research team demonstrated that the approach could resolve the minute amount of microRNAs that can be found in patients. Next steps will involve expanding the technology to study clinical samples of blood, tissue, or urine.
Hall holds a provisional patent on this technology.
1. Zahid OK, Wang F, Ruzicka JA, et al. Sequence-specific recognition of microRNAs and other short nucleic acids with solid-state nanopores [published online ahead of print January 29, 2016]. Nano Lett. doi:10.1021/acs.nanolett.6b00001.