A new technique has been developed utilizing nanotechnology to detect disease biomarkers in the form of nucleic acids. The proof-of-concept study came from a team of researchers at Wake Forest Baptist Medical Center (NC, USA), and was published recently in Nano Letters.
“We envision this as a potential first-line, noninvasive diagnostic to detect anything from cancer to the Ebola virus,” commented Adam R Hall (Wake Forest Baptist Medical Center), 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 order of bases in nucleic acid chains are tightly linked to their function and thus can be used to indicate what is going on inside cells, acting as signals for disease. For example, the small noncoding family of miRNAs are only approximately 20 bases long but can be used as an indicator of many diseases, including cancer. However, as Hall points out, “…one problem has been accurate detection because they are so short, many technologies have real difficulty identifying them.”
The new technique is capable of determining the presence (or absence) of a specific nucleic acid sequence in a given mixture using nanotechnology; furthermore, if a nucleic acid sequence is present, the technique can quantify this using a simple electronic signature. Hall explained: “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 … By simply counting the number of signals, you can determine how much of the target is around.”
The researchers initially showed that the method was capable of effectively identifying a specific sequence among a background of competing nucleic acids, and then proceeded to apply the technique to mi-R155, a miRNA known to indicate the presence of lung cancer in humans. The results demonstrated that the technique could resolve the tiny levels of miRNAs found in patients. The researchers now plan to expand the technology to study clinical samples of urine, blood or tissue.