A multi-volume microfluidic device with no reagent loss for low-cost digital PCR application

Abstract A multi-volume multi-level vertical branching microchannel microfludic chip is presented in this study for low-cost and easy-operation digital PCR (dPCR). The chip with multi-volume design can achieve a dynamic range of over 104 for nucleic acid quantification with only 1792 chambers, which consist of two types of chambers with different volumes and quantities. Meanwhile, the dPCR chip realizes 100% sample compartmentalization without any loss. In addition, the chip can partition samples autonomously in a simple way through negative pressure provided by a degassed PDMS layer. Furthermore, a glass-PDMS-glass “sandwich” structure was employed in the chip to form a robust support. The quantitative capability of the digital PCR chip is evaluated by measuring a 10-fold serial dilution of the KRAS plasmid template. Owing to its characteristics of easy operation process, low cost, relative wide dynamic range, and no sample loss, the proposed dPCR chip is expected to further promote the extensive application of digital PCR, especially in the POCT field.