Cylindrical pillars in silicon PCR chip enhance the performance of DNA amplification

Abstract

This paper presents a new design of a silicon PCR chamber with cylindrical pillars on the bottom which showed good performance in heat transfer and DNA amplification efficiency comparable to thermocycler. We successfully amplified the full DNA sequence of N-acetyl transferase 2 (NAT2) gene, cancer related gene, from the genomic DNA. NAT2 transfers the acetyl moiety to toxic compounds coming into the cell. Acetylated toxic compounds may change their 3D structure and lose toxic activities. We observed temperature difference between top and bottom of PCR mixture even by more than 7/spl deg/C when general PCR micro chamber was heated and adjusted to be a constant temperature by electric power (data not shown). This may influence bad effects on the yield and reproducibility of DNA amplification in PCR lab-on-a-chip. Cylindrical pillars expanding surface area facing to PCR mixture are thought to be helpful to get higher efficiency of heat transfer. We also made a thin film type of heater through FPC manufacturing process. That requires low cost and is applicable for mass production. Pillar-formed PCR chamber and FPC film heater showed good performance of DNA amplification, comparable to thermocycler and higher than that of nonpillar PCR chamber.