Electrochemical cell lysis device for DNA extraction

We present a novel electrochemical cell lysis device to prepare DNA samples for lab-on-a-chip (LOC) applications. It utilizes the electrolysis of saline solution to generate hydroxide ions (OH-) at the cathode as alkaline lytic agents. Cathode and anode chambers are separated by a negatively-charged ion exchangeable polymer diaphragm to maintain the high pH level for efficient cell lysis in the cathode chamber, to prevent inflow of PCR-amplification inhibitors from the anode chamber, and to minimize binding of DNA molecules. Electric current flow and pH maintenance, which depended on the device design, were two important parameters of the device performance. After optimizing the design and visually confirming cell lysis of Chinese hamster ovary (CHO) cells in a very short amount of time, we directly electrolyzed four bacterial cell types suspended in saline solution. Real-time PCR (qPCR) analysis showed that our device could lyse both gram-positive and gram-negative bacterial cells with higher efficiency than other common methods and could detect DNA on the microlitre scale. Our data demonstrate several advantages of the proposed device: absence of cell lysis chemicals and heating; no adverse effects on PCR amplification; low DNA loss; low voltage and power consumption; and rapid processing. The device could potentially be applied as an on-chip DNA extraction component.