Patent ID: 6432637
Filing Date: 2002-08-13
Classification: C07H,C12Q

Abstract:
A method for determining a base sequence of a nucleotide strand comprising the steps of:(a) providing a first probe, comprising a fluorescent metal-ligand complex coupled to a first oligonucleotide having a sequence complementary to a first fragment of said strand; (b) adding said first probe to a sample that contains said first fragment to form a first mixture containing a first reaction product of said first probe and said first fragment; (c) exposing said first mixture to an exciting amount of radiation; (d) detecting fluorescence of said first metal-ligand complex; (e) identifying a first base sequence of said first fragment based on fluorescence of said first metal-ligand complex; (f) providing a second probe, comprising a second fluorescent metal-ligand complex coupled to a second oligonucleotide having a sequence complimentary to a second fragment of said strand differing from said first fragment by at least one base; (g) adding said second probe to a sample that contains said second fragment to form a second mixture containing a second reaction product of said second probe and said second fragment; (h) exposing said second mixture to an exciting amount of radiation; (i) detecting fluorescence of said second metal-ligand complex; (j) identifying a second base sequence of said second fragment based on fluorescence of said second metal-ligand complex; (k) comparing said second base sequence with said first base sequence to identify a difference between the first and second sequences and thereby determine a base sequence of said nucleotide strand; wherein the metal in each said fluorescent metal-ligand complex is selected from the group consisting of Co, Cr, Cu, Mo, Rh, W, Re, Os, Ir, and Pt; wherein said detection utilizes measurement of fluorescence lifetime; and wherein autofluorescence is suppressed by fluorescence gating.