The microfluidic devices and systems disclosed herein reduce sample loss and help decrease sample processing bottlenecks for applications such as next generation sequencing (NGS). The microfluidic devices include a plurality of reaction modules. Each reaction module may comprise one or more reaction circuits. Each reaction circuit may comprise a single reaction flow channel with each reaction circuit connected by a bridge flow channel. Alternatively, each reaction circuit may comprise two or more reaction flow channels connected by two or more bridge flow channels. The combination of any two bridge flow channels and a portion of the two or more reaction flow channels between the any two bridge flow channels defining may define the reaction circuit. The reaction module may be arranged as nodes connected by bridge flow channels or each reaction module may be arranged in a parallel fashion on the microfluidic device.
