DETECTION OF DIFFERENCES BETWEEN POLYNUCLEOTIDES

摘要

A method is disclosed for detecting the presence of a difference between two related nucleic acid sequences. A complex is formed comprising both of the nucleic acid sequences in double stranded form. The complex comprises at least one pair of non-complementary strands and each of the non-complementary strands within the complex has a label. The complex is subjected to conditions wherein, if a difference between the two related nucleic acid sequences is present, strand exchange in the complex ceases and wherein, if no difference between the two related nucleic acid sequences is present, strand exchange in the complex continues until complete strand exchange occurs. A first signal is detected from the association of the labels as part of the complex. The association of the labels is related to the presence of the difference. A complex is also formed comprising the nucleic acid sequence suspected of comprising a difference in double stranded form and a predetermined amount of a non-relevant reference polynucleotide in double stranded form. The complex comprises at least one pair of non-complementary strands and each of the non-complementary strands within the complex has a label. A second signal from the association of the labels as part of the above complex is detected. A ratio of the first signal to the second signal is determined and related to the presence of the difference.