DNA methylation analysis on a droplet-in-oil PCR array.

We performed on-chip DNA methylation analysis using methylation-specific PCR (MSP) within an arrayed micro droplet-in-oil platform that is designed for more practical application of microfluidic droplet technologies in clinical applications. Unique features of this ready-to-use device include arrayed primers that are pre-deposited into open micro-reaction chambers and use of the oil phase as a companion fluid for both sample actuation and compartmentalization. These technical advantages allow for infusion of minute amounts of sample for arrayed MSP analysis, without the added complexities inherent in microfluidic droplet-based studies. Ease of use of this micro device is exemplified by analysis of two tumor suppressor promoters, p15 and TMS1 using an on-chip methylation assay. These results were consistent with standard MSP protocols, yet the simplicity of the droplet-in-oil microfluidic PCR platform provides an easy and efficient tool for DNA methylation analysis in a large-scale arrayed manner.