Microfluidic chip for high efficiency DNA extraction

Abstract

A high efficiency DNA extraction microchip was designed to extract DNA from lysed cells using immobilized beads and the solution flowing back and forth. This chip was able to increase the extraction efficiency by 2-fold when there was no serum. When serum existed in the solution, the extraction efficiency of immobilized beads was 88-fold higher than that of free beads. The extraction efficiency of the microchip was tested under different conditions and numbers of E. coli cells. When the number of E. coli cells was between 10⁶ and 10⁸ in 25 µl of whole blood, the extraction efficiency using immobilized beads was only slightly higher than that using free beads (10⁰ to 10¹ fold). When the number of E. coli cells was in the range 10⁴ to 10⁶ in 25 µl of whole blood, the extraction efficiency of immobilized beads was greater than that of the free beads (10¹ to 10² fold). When the number of E. coli cells was lower, in the range 10³ to 10⁴ in 25 µl of whole blood, the extraction efficiency of immobilized beads was much higher than that of the free beads (10² to 10³ fold). This study indicated that DNA could be efficiently extracted even when the number of bacterial cells was smaller (10⁵ to 10³). This microfluidic extraction chip could find potential applications in rare sample genomic study.