Method for determining a concentration of target nucleic acid molecules, nucleic acid probes for the method and method for analyzing data obtained by the method

A method for determining a concentration of a target nucleic acid, which comprises hybridizing a nucleic acid probe which is labeled with only a fluorescent dye to said target nucleic acid,

• wherein only said nucleic acid probe is provided for one type of target nucleic acid,
• 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,
• wherein said fluorescent dye is reduced in fluorescence emission when said probe is hybridized with said target nucleic acid;
• and
• measuring a decrease in fluorescence emission from said fluorescent dye after said hybridization relative to fluorescence emission from said fluorescent dye before said hybridization.