e15019 Background: Liquid biopsy has evolved to be an important method complementary to tissue biopsy. It is not only non-invasive, but also has the potential to detect cancer in its earliest stages and monitor patients in remission. The integration of proteomics into liquid biopsy may transform the molecular diagnostics of cancer and accelerate basic and clinical oncology research. A recent study showed that adding just 8 protein biomarkers to a panel of circulating DNA biomarkers increased the diagnostic accuracy up to 98% sensitivity and 99% specificity. Proteomics also bridges the gaps of functional information lost due to post-transcriptional and post-translational modifications in the genomic approach. However, the proteogenomic approach normally requires the use of multiple different assay technologies and laboratory workflows, including mass spectrometry. Methods: NanoMosaic’s Tessie platform employs a densely integrated nanoneedle sensor array (thus named MosaicNeedles) which can be used to detect both nucleic acids and proteins in a single assay process with reduced workflow complexity, without the need for mass spectrometry. Results: The NanoMosaic platform is a label-free, digital, single molecule counting technology using nanoneedles. It achieves sub-pg/ml (̃fM) level sensitivity with 7 logs of dynamic range. An array of nanoneedles is densely integrated and manufactured with CMOS-compatible nanofabrication processes. Each nanoneedle is a single molecule biosensor that is functionalized with capture probes. The capture probe can be either an antibody for protein detection or an oligonucleotide with a specific target sequence to a DNA fragment, mRNA, or miRNA of interest. The scattering spectrum of each nanoneedle changes when an analyte binds to its surface. At low abundance, analytes that are captured can be quantitated by counting the presence or absence of a color change on each individual nanoneedle in a binary fashion. As an analyte concentration increases the binding events increase accordingly and achieve saturation. In this range, an analog analysis on the spectrum shift will be performed, thus providing a wider dynamic range, up to 7 logs. Ultrahigh level multiplex can be achieved by parallelizing each analyte specific sensing area without loss of sensitivity or dynamic range. A 10,000-plex study can be achieved with a total of 2.5 billion nanoneedles on a 50mm by 50mm consumable. In this consumable, a 2,000-plex proteome and 8,000 cell-free DNA fragments can be detected. Conclusions: In conclusion, a full proteogenomic quantification can be performed on the NanoMosaic platform in one reaction, with higher sensitivity, lower cost and higher throughput than is currently possible by traditional methods. In addition, the high-plexibility of the NanoMosaic platform allows the discovery of new biomarkers across the whole proteome without the need for mass spectrometry.
Multiplex Enrichment and Detection of Rare KRAS Mutations in Liquid Biopsy Samples using Digital Droplet Pre-Amplification