title: A simple device using magnetic transportation for droplet-based PCR.
abstract: The Polymerase chain reaction (PCR) was successfully and rapidly performed in a simple reaction device devoid of channels, pumps, valves, or other control elements used in conventional lab-on-a-chip technology. The basic concept of this device is the transportation of aqueous droplets containing hydrophilic magnetic beads in a flat-bottomed, tray-type reactor filled with silicone oil. The whole droplets sink to the bottom of the reactor because their specific gravity is greater than that of the silicone oil used here. The droplets follow the movement of a magnet located underneath the reactor. The notable advantage of the droplet-based PCR is the ability to switch rapidly the proposed reaction temperature by moving the droplets to the required temperature zones in the temperature gradient. The droplet-based reciprocative thermal cycling was performed by moving the droplets composed of PCR reaction mixture to the designated temperature zones on a linear temperature gradient from 50 degrees C to 94 degrees C generated on the flat bottom plate of the tray reactor. Using human-derived DNA containing the mitochondria genes as the amplification targets, the droplet-based PCR with magnetic reciprocative thermal cycling successfully provided the five PCR products ranging from 126 to 1,219 bp in 11 min with 30 cycles. More remarkably, the human genomic gene amplification targeting glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was accomplished rapidly in 3.6 min with 40 cycles.
authors.affiliation: Life Science Laboratory, Analytical and Measuring Instruments Division, Shimadzu Corporation, Kyoto, 604-8511, Japan. tetu@shimadzu.co.jp
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ohashi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kuyama
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Hanafusa
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Togawa
mesh_terms: D020029:Base Pairing; D004247:DNA / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D004867:Equipment Design; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D006801:Humans; D008280:Magnetics; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D016133:Polymerase Chain Reaction / Q000295:instrumentation* / Q000379:methods; D013696:Temperature; D013997:Time Factors
chemical_list: D004272:DNA, Mitochondrial; D004247:DNA; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases