Biomarkers based on DNA methylation have attracted wide attention in biomedical research due to their potential clinical value. Therefore, a sensitive and accurate method for DNA methylation detection is highly desirable for the discovery and diagnostics of human diseases, especially cancers. Here, an integrated, low-cost, and portable point-of-care (POC) device is presented to analyze DNA methylation, which integrates the process of pyrosequencing in a digital microfluidic chip. Without additional equipment and complicated operation, droplets are manipulated by patterned electrodes with individually programmed control. The system exhibited an excellent sensitivity with a limit of detection (LOD) of 10 pg and a comparable checkout down to 5% methylation level within 30 min, which offered a potential substitute for the detection of DNA methylation. With the advantages of portability, ease of use, high accuracy, and low cost, the POC platform shows great potential for the analysis of tumor-specific circulating DNA.
Keywords: DNA methylation; ctDNA; digital microfluidics; epigenetic biomarker; point-of-care testing.