Patent ID: 8624016

Claim:
An apparatus comprising: a solid support having an array of positions; composite oligonucleotides coupled to the solid support at the array of positions, each of said composite oligonucleotides characterized by having a target-specific portion and a zip code portion, wherein the zip code portion of each of the composite oligonucleotides comprises a nucleotide sequence of greater than sixteen nucleotides that differs for each different target-specific portion and hybridizes to its complement under uniform hybridization conditions, wherein the nucleotide sequence of one zip code portion differs from the nucleotide sequence of another zip code portion, when aligned to each other, by at least 25% of the nucleotides; and one or more detectable labels coupled to at least one of the composite oligonucleotides, thereby facilitating detection of the composite oligonucleotide and its zip code portion.