This paper reports the completion of a parallel ultramicro-volume DNA ligation processes using a coplanar electrode type of electrowetting-on-dielectric (EWOD) microfluidic system. The droplets, containing DNA, a ligation enzyme and a multi-salt reaction buffer, served to complete the ligation using a developed EWOD system. In order to reduce the effect from environment, so the concept of core-shell droplet was used in this study. Droplets of ultramicro volume (0.3 muL) were successfully generated from reservoirs between one plate with coplanar electrodes and another plate with a hydrophobic surface free of electrodes. In one successful cloning, the total usage of reagents in an ultramicro-volume EWOD chip was 2.1 muL; no volume was wasted, in comparison with 85% waste with the standard protocol (15 muL). The results also show that the four parallel DNA ligation processes were accomplished without damage to the chip surface and without biomaterial annulment.
Solid-State Sensors, Actuators and Microsystems Conference, 2009. TRANSDUCERS 2009. International; 07/2009