Patent ID: 6682887
Filing Date: 2004-01-27
Classification: C07H,C40B

Abstract:
A method for detecting at least one nucleic acid sequence in a target nucleic acid sample, said method comprising:combining under primer extension conditions: a polymerase having 5â€²-3â€² exonuclease activity, said target DNA and a reagent pair consisting of a primer and a detection sequence comprised of nucleotide bases for each DNA sequence to be determined, wherein each said primer specifically binds to said target DNA and said detection sequence binds to said target DNA downstream from said primer in the direction of primer extension, wherein each said detection sequence is characterized by having an electrophoretic tag specific for each said DNA sequence and at least one nucleotide linkage at positions immediately 3â€² of the second nucleotide at the 5â€²-end of said oligonucleotide that is resistant to nuclease hydrolysis; executing at least one cycle of said primer extension, whereby said detection sequence bound to target DNA is at least partially degraded with release of said electrophoretic tag substantially free of said detection sequence, such that cleavage of the detection sequence at its 5â€² end by the 5â€²-3â€² exonuclease produces a single released product composed of the electrophoretic tag and the 5â€²-end nucleotide of the detection sequence, wherein each said released product produced from a given detection sequence has a known, unique electrophoretic mobility with respect to the released products produced from all other such detection sequences, by virtue of a unique charge/mass ratio associated with the electrophoretic tag; separating said released products into individual fractions of released products specific for each DNA sequence; and detecting, by means of said released product, said fractions, whereby the presence in said target DNA sample of said at least one DNA sequence is detected.