Patent ID: 7306918
Filing Date: 2007-12-11
Classification: B82Y,C12Q

Abstract:
1. A method of determining the number of tandem nucleotide repeats in a target nucleic acid sequence, wherein said tandem repeats are flanked at each side by a non-repeat flanking sequence, the method comprising the following steps: (a) providing a set of oligonucleotide probes attached to beads, said beads being associated with a chemically or physically distinguishable characteristic that uniquely identifies the probes attached thereto, said probes capable of annealing to the target nucleic acid sequence and containing an interrogation site, wherein probes in the set differ in a the number of contiguous repeated subsequences they contain, such that when the probes are annealed to the target sequence, the interrogation sites of probes are aligned with a target site which is located within the repeated subsequences or not; (b) contacting a target sequence to said probes, under conditions so that said target sequence forms hybridization complexes with said probes; (c) interrogating the hybridization complexes between the target sequence and the probes, to determine which probes have their interrogation sites outside the repeated subsequences and which probes do not; and (d) decoding the set of probes using the distinguishable characteristic of the beads, and based on which probes do and do not have their interrogation sites outside the repeated subsequences, such that the number of contiguous repeated subsequences in probes in hybridization complexes which have their interrogation sites outside the repeated subsequences in the targets represent the number of repeats in the target sequence.