Hybridization methods using natural base mismatches

4-9. (canceled)

A process for discriminating between a first nucleic acid target and a second nucleic acid target in a test sample wherein the second nucleic acid target has a sequence variation relative to the first target, the process comprising the steps of:

• providing an oligonucleotide having a nucleic acid sequence complementary in part to the first target, including at the position of the sequence variation, but comprising an artificially mismatched naturally occurring nucleotide base relative to the targets at a position other than that of the sequence variation, the artificially mismatched base and the sequence variation positions being separated from one another on the oligonucleotide by six to nine nucleotide positions;
• combining the oligonucleotide and the test sample under selected hybridization conditions to form a product from the group consisting of (a) a first duplex comprising the oligonucleotide and the first target, (b) a second duplex comprising the oligonucleotide and the second target and being less stable than the first duplex, and (c) a mixture comprising both the first duplex and the second duplex;
• selectively detecting the first duplex comprising the oligonucleotide and the first target or the second duplex comprising the oligonucleotide and the second target.