We present an endpoint PCR product sensing system for online detection of double-stranded DNA (dsDNA) down to 1 ng/mu l in a flow-through design with a throughput of up to 144 samples per hour. The device is assembled from off-the-shelf microfluidic and optical components with a chamber volume of 520 nl without any lenses. Fluorescence sensing is realized with a LED-Photodiode combination, which makes this system practicable for every lab. The direct combination with a continuous-flow PCR system realises an integrated diagnostic device for pathogen detection (C) 2011 Published by Elsevier Ltd.