Assembly of a random array. (A) Creation of a bead pool and assembly into ∼3-μm-diameter wells etched in optical fiber bundles. Once a bead pool is made, it is relatively straightforward to assemble and decode large numbers of arrays. Each array contains ∼50,000 beads distributed among 1520 bead types, so that each bead type is represented at ∼30-fold redundancy. Scanning electron micrographs are shown of an unassembled and an assembled array containing one bead per well. (B) Because individual arrays are only ∼1.4 mm in diameter, they can easily be arranged into a 96-array matrix, designed for parallel analysis of samples in standard microtiter plates.
