DNA detection method based on the microbead velocity under traveling wave dielectrophoresis

Polymerase chain reaction (PCR) is a highly specific and sensitive detection method for bacterial and viral infections by amplifying the specific regions of DNA or RNA via enzymatic reaction. The authors have developed a rapid DNA detection method based on the dielectrophoresis (DEP) characteristic of DNA labeled microbeads for the rapid detection of the DNA that amplified by PCR. This method is based on the change of the Clausius-Mossotti (CM) factor K of DEP when DNA is attached onto microbeads. In former studies, we developed a new DNA detection method based on the change of the real part of K (Re[K]). However, this method requires a large amount of DNA attaching to a microbead to alter the microbead DEP behaviour for DNA detection. In this study, we focus on the imaginary part of K (Im[K]), which theoretically will change more dramatically than Re[K] when DNA is attached onto the microbeads. Since the traveling wave dielectrophoresis behaviour is based on the Im[K], we propose a new method for DNA detection based on the traveling wave dielectrophoresis (twDEP) of microbeads.