Patent ID: 7319003

Claim:
An array of nucleic acid probes, wherein each probe comprises: a single-stranded first nucleic acid of about 15–25 nucleotides in length; a longer single-stranded second nucleic acid of about 20–30 nucleotides in length, comprising a nucleotide sequence complementary to the first nucleic acid and a random terminal nucleotide sequence of between 3–10 nucleotides in length; and an oligonucleotide of 4–20 nucleotides in length, comprising a random nucleotide sequence, wherein: the first nucleic acid is hybridized to the second nucleic acid to form a hybrid having a double-stranded portion and a single-stranded portion comprising the random terminal nucleotide sequence of between 3–10 nucleotides in length; and the oligonucleotide is ligated to the random nucleotide sequence of the second nucleic acid.