Digital DNA Sequence Profiling of Rare Epigenetic Cancer Biomarkers in A Highly Parallelized Microfluidic Platform

We present a microfluidic platform for molecule-by-molecule detection of heterogeneous epigenetic patterns of rare tumor-derived DNA by highly parallelized digital melt assessment. We introduce a multilayer geometric strategy to capture single molecules in a pico-array at high efficiency. We demonstrate sensitive detection and comprehensive profiling of rare heterogeneously methylated DNA of a classic tumor suppressor gene, p14 ^ARF , at frequencies as low as 0.0001% methylated/unmethylated.