Abstract: A method of assaying genetic sequences comprises introducing double stranded DNA to be assayed into an aqueous buffer medium containing complexes of an anchor DNA strand anchored to a support matrix and hybridized with a reporter DNA strand having a detectable label. A portion of the anchor strand or the reporter strand consists of a selected sequence of bases capable of forming a triple helix or triple strand structure with a portion of particular double stranded DNA. The reporter strand is displaced from the complex upon formation of a triple helix or triple strand structure, and displaced reporter strands are detected to determine the presence of the particular double stranded DNA. Gene probes, anchor/reporter hybrids, selected gene sequences and kits, useful in the assay method, are provided.