Patent ID: 7135284

Claim:
A method of labeling an oligonucleotide, comprising the steps of: (a) hybridizing a first oligonucleotide to a second oligonucleotide, wherein the first oligonucleotide consists of, from 3′ to 5′: a Substrate Hybridization Domain adjoining a Signal Template Domain, wherein: the Substrate Hybridization Domain consists of a sequence of about 5 to about 20 nucleotides and cannot be extended by a 5′→3′ DNA polymerase; and the Signal Template Domain consists of a sequence of about 5 to about 100 nucleotides; and the second oligonucleotide comprises; from 3′ to 5′: a Template Hybridization Domain adjoining a Target Binding Domain, wherein: the Template Hybridization Domain consists of a sequence of about 5 to about 20 nucleotides which is not detectably labeled, has 5 or more bases complementary to the Substrate Hybridization Domain of the first oligonucleotide, and is hybridizable to the Substrate Hybridization Domain of the first oligonucleotide; and the Target Binding Domain is not detectably labeled and comprises a nucleotide sequence heterologous to that of the Template Hybridization Domain and to that of the first oligonucleotide; and (b) extending the second oligonucleotide with a DNA polymerase in the presence of labeled nucleotides to create an oligonucleotide Probe having from 5′ to 3′ an unlabeled Target Binding Domain adjoining a Template Hybridization Domain adjoining a labeled Signal Domain.