particles such as cells or beads suspended in the liquid sediment into the trench possessing an aspect ratio
adapted to the chosen flow conditions. Now a sequence of other liquids can be provided to the permanently retained
particles, e.g. culture medium, wash or lysis buffers, biochemical reagents such as PCR master mix and detection
labels. By diffusive mixing, the particles are successively exposed to these liquids. As a pilot application, we
implemented a NASBA based nucleic acid test, but also bead based immunoassays can be implemented with the
same scheme