A method for the selective amplification of a target sequence. The method includes hybridizing a tagged oligonucleotide to the target sequence and reducing the effective concentration of unhybridized tagged oligonucleotide which is capable of hybridizing to the target sequence. The tagged oligonucleotide includes a target hybridizing sequence and a tag sequence situated 5′ to target hybridizing sequence, where the tag sequence does not stably hybridize to a target nucleic acid containing the target sequence. A blocker oligonucleotide is provided which is designed to hybridize to a region of a nucleic acid containing the target sequence, where the region targeted by the blocker oligonucleotide is 3′ to the target sequence. Amplification products are formed using first and second oligonucleotides. The first oligonucleotide hybridizes to the 3′-end of the complement of the target sequence, and the second oligonucleotide hybridizes to the complement of the tag sequence.