A microfluidic device comprising a microfluidic channel network sealed on one side by a membrane sheet, the sheet having PDMS defining at least the surface sealing the channel, the membrane sheet on its opposite side sealing one side of a pneumatic channel, the pneumatic channel arranged to enable pneumatic deflection of a deflectable portion of the membrane sheet into contact with an opposed surface to control flow in a channel of the network, the membrane sheet confining in a channel of the network at least one micro-particle, micro-length tube or glass nano reactor, functionalized with a capture agent, that has been inserted into that channel. A microfluidic device having a microfluidic channel containing at least two micro-particles, micro-length tubes or glass nano reactors, one functionalized with nucleic acid and another with antibody or antigen. A microfluidic device having a microfluidic channel containing at least one micro-length tube or glass nano reactor functionalized to capture nucleic acid, the device constructed to enable recovery of the nucleic acid captured by the device.