A continuous electrical cell lysis device using a low dc voltage for a cell transport and rupture

We present a continuous and low voltage cell lysis device in which a width and length of a channel change to generate focused the high electric field strength for cell lysis and the low electric field strength for a transport of samples. The previous cell lysis devices acquire the high electric field strength for a cell lysis by applying an ac voltage to a micro-gap between electrodes and require additional pumps or valves for a sample transport. However, when we change the width and length of the channel between a pair of external electrodes attached to a dc voltage, we generate both the high electric field strength for a cell lysis and the low electric field strength for an electroosmotic flow. The present device therefore performs continuous cell lysis and a sample transport without needing either an additional flow source or an additional process fabricating the electrodes for the micro-gap. The experimental study features an orifice whose width and length is 20 times narrower and 175 times shorter than the width and length of a microchannel. With an operational voltage of 50 V, the present device generates high electric field strength of 1.2 kV/cm at the orifice to disrupt cells with 100% lysis rate of red blood cells and low electric field strength of 60 V/cm at the microchannel to generate an electroosmotic flow of 30 +/- 9 mu m/s. In conclusion, the present device is capable of continuous self-pumping cell lysis at a low voltage; thus, it is suitable for a sample pretreatment component of a micro total analysis system or lab-on-a-chip. (c) 2006 Elsevier B.V. All rights reserved.