Integrated droplet microfluidic device for magnetic particles handling: Application to DNA size selection in NGS libraries preparation

•Integration of magnetic microstructures for surface-functionalized magnetic particles handling in droplets.•Particles extraction, redispersion and clean-up in an unique microfluidic device.•In-droplet DNA size-selection for NGS library preparation workflows. We present an innovative droplet microfluidic device based on integrated soft-magnetic structures allowing extraction, redispersion and depletion processes of magnetic particles. Following a numerically-assisted conception, the device was at first fabricated and experimentally characterized, showing reliable and efficient magnetic particles extraction with a low carryover of the initial matrix (