Bead Arrays in PDMS Wells for Multiplexed Screening Assays

Spectrally-encoded microbeads are deposited in wells on the surface of a PDMS microchannel to create a registry suitable for probing ligand-receptor binding interactions such as those of interest in pharmaceutical development (“lab on a chip”). We have demonstrated gravity-based deposition of fluorescently labeled glass beads in wells on a PDMS surface passivated with PEG. Sequential loading of bead sets, each labeled to identify a unique ligand grafted to its surface, create an addressable array over which fluorescently labeled receptors selectively bind to target ligands, identifying the receptor-ligand complex. To validate the technique, we investigated the well-known avidin-biotin reaction.