DNA detection using microbeads-based dielectrophoretic impedance measurement

A new electrical technique for rapid detection of DNA amplified by polymerase chain reaction (PCR) using dielectrophoresis (DEP) of microbeads was demonstrated. The amplicons were chemically immobilized on the microbeads. The DNA immobilization on the microbeads alters their DEP behavior in such a way that they are trapped on a microelectrode under the action of positive DEP, whereas pristine microbeads are not. Combining the dramatic alteration in DEP characteristics with impedance measurement leads to rapid and quantitative detection of the amplicon in a few seconds. The proposed microbead-based assay could be applicable for rapid, quantitative, and automated detection of virus infection.