Lab Chip 2012 Apr 15;12(7):1289-95. Epub 2012 Feb 15.
Biomedical Diagnostics Institute, National Centre for Sensor Research, School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
We present a novel centrifugal microfluidic platform for the highly efficient manipulation and analysis of particles for applications in bead-based assays. The platform uses an array of geometrical V-cup barriers to trap particles using stopped-flow sedimentation under highly reproducible hydrodynamic conditions. The impact parameters governing the occupancy distribution and capture efficiency of the arrayed traps are investigated. The unique, nearly 100% capture efficiency paired with the capability to establish sharply peaked, single occupancy distributions enables a novel, digital readout mode for color-multiplexed, particle-based assays with low-complexity instrumentation. The presented technology marks an essential step towards a versatile platform for the integration of bead- and cell-based biological assays.