Patent ID: 7429655

Claim:
A nucleic acid probe for determining a concentration of a target nucleic acid, said probe being labeled with a fluorescent dye, wherein: said probe is labeled at an end portion thereof with said fluorescent dye, and said probe has a base sequence designed such that, when said probe is hybridized with said target nucleic acid, at least one G (guanine) base exists in a base sequence of said target nucleic acid at a position 1 to 3 bases apart from an end base portion where said probe and said target nucleic acid are hybridized with each other; whereby said fluorescent dye is reduced in fluorescence emission when said probe is hybridized with said target nucleic acid, wherein said probe is labeled at the 3′ end thereof with said fluorescent dye and wherein the fluorescent dye is BODIPY FL, BODIPY 5-FAM, or BODIPY TR, wherein said fluorescent dye is labeled to said probe with a spacer containing from 4 to 7 methylene units.