A microfluidic bioreactors consists of two chambers separated by a nanoporous silicon membrane. It allows for flow-based assays using minimal amounts of reagent. The ultra-thin silicon membrane provides an excellent mimic of biological barrier properties. NOTE: This image combines two exposures in order to capture the brighter and darker parts of the scene, which exceed the dynamic range of the camera sensor. The resulting composite is truer to what the eye actually sees. (Credit: Adam Fenster/University of Rochester)

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