Fall 2013 IAB & Research Review
September 18 - 19
One-Step Point-of-Care Quantitative Nucleic Acid Detection based on Digital Plasma Separation [BPN679]
Nucleic acid-based (NA) assays have the highest sensitivity and selectivity for quantitative diagnostics (e.g., HIV; MRSA). However, current blood-based molecular diagnostics for quantitative NA detection requires many sample preparation steps and costly machines such as a real-time thermal cycler. Here we have developed an integrated system, termed “Digital Plasma Separation (DPS),” which allows quantitative NA detection by integrating sample prep, NA amplification and detection into one device. DPS combines autonomous parallel plasma separation and sample compartmentalization in a one-step process. This method removes blood cells that may interfere with endpoint fluorescence readout. Simple fluorescence endpoint observation of positive wells can be analyzed by a smartphone. We demonstrated that DPS is compatible with quantitative isothermal nucleic acid amplification (using Recombinase Polymerase Amplification). As an example, DPS enabled a one-step HIV-RNA assay directly from whole blood in 30 min (dynamic range 1E3 ~ 1E5 copies/ml). This project is expected to be an alternative low-cost solution for quantitative NA assays compared to conventional bench-top assays.