At University of California Los Angeles, researchers have developed a portable device and accompanying technology that allows the investigators to amplify and detect DNA and RNA molecules. This development may herald cheap point-of-care genetic diagnostics for cancer, infectious diseases, and even inherited genetic conditions.
Previously, intercalator dyes, which are molecules that attach to nucleic acids and emit a fluorescent light, have been used for cheap optical detection of genetic material. These dyes are short lived and produce a weak light that is difficult to detect, limiting such techniques. The UCLA team found a compound that increases the brightness of the intercalator dyes, allowing a smartphone camera coupled with some additional components to detect their glow.
The amplification is performed inside a 96-well microplate to which a fiber optic bundle is attached so that each well is linked via a unique fiber to a section of a smartphone camera’s sensor. As the fluorescent dyes are energized, they glow and dots appear on the screen of the wells in which the target genetic material is present.
Some details from the study abstract in ACS Nano:
Using loop-mediated isothermal amplification on lambda DNA we achieve a 69-fold increase in signal above background, 20-fold higher than the gold standard, yielding an overall limit of detection of 25 copies/μL within an hour using our mobile-phone-based platform. Critical for a point-of-care system, we achieve a >60% increase in fluorescence stability as a function of temperature and time, obviating the need for manual baseline correction or secondary calibration dyes.
Study in journal ACS Nano: Highly Stable and Sensitive Nucleic Acid Amplification and Cell-Phone-Based Readout…
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