Patent ID: 7951604

Claim:
A method for assaying at least one target nucleic acid, the method comprising contacting the at least one target nucleic acid with a mixture comprising: (A) at least one target nucleic acid probe, and (B) an internal standard nucleic acid; and assaying the at least one target nucleic acid after said contacting, wherein the at least one target nucleic acid probe (A) has a base sequence hybridizable with a portion of the base sequence of the at least one target nucleic acid and the at least one target nucleic acid probe is labeled at a 5′-end or 3′-end with a fluorescent dye which can be fluorescence-quenched by interacting with guanine, the internal standard nucleic acid (B) has a base sequence portion that is the same as the portion of the at least one target nucleic acid except that one of a first to a third base in the base sequence of the portion of the at least one target nucleic acid has been switched with another base in the base sequence of the portion of the at least one target nucleic acid, wherein one of the switched bases is guanine, and wherein the first base is the base of the target nucleic acid or internal standard nucleic acid opposite the labeled base of the target nucleic acid probe when the target nucleic acid or internal standard nucleic acid is hybridized to the target nucleic acid probe.