Patent ID: 7052841

Claim:
A sandwich hybridization system comprising: an apparatus having a first plurality of oligonucleotide probes attached to a substrate, each first probe of the first plurality comprising: a first sequence of nucleotides having either a (3′→5′) or (5′→3′) polarity; and at least one first nucleotide that has a reversed polarity relative to the polarity of the first sequence; and a second plurality of biological probes, each second probe of the second plurality comprising a first oligonucleotide region and a second region, the first oligonucleotide region comprising: a second sequence of nucleotides having the same polarity as the polarity of the first sequence, and are respectively complementary to the first sequence of nucleotides, and at least one second nucleotide tat is complementary to the at least one reversed polarity first nucleotide, the second nucleotide having a reversed polarity relative to the polarity of the second sequence, wherein the second region is complementary to a biological material to be assayed, and wherein the reversed polarity first nucleotide and the complementary reversed polarity second nucleotide preferentially hybridizes to each other during the assay than to a complementary nucleotide whose polarity is not similarly reversed.