A flow-through PCR device with integrated chromium resistive heaters was developed. The PCR device was composed of a polydimethylsiloxane flow channel chip fabricated using soft lithography and a glass heating chip produced by standard photolithography. PDMS bonding layers were used to assemble the device instead of oxygen plasma treatment. The formation of air bubbles within the device was suppressed by treating the flow channel with 20% (v/v) Tween 20. DNA fragments with different lengths (219, 298, and 842 bp) were successfully amplified with the device. For the 298 bp fragment, 30 thermal cycles were completed in 23 min and a clear product band was observed after gel electrophoresis. The device showed no cross contamination after appropriate washing. Two commonly used PCR additives, bovine serum albumin and polyethylene glycol, showed inhibitory effect in the Tween 20 treated PCR device. (C) 2007 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.