Patent ID: 7449298

Claim:
A method of analyzing polynucleotide, comprising the steps of: (a) forming a plurality of differently-sized fluorescently labeled extended oligonucleotide primers that are complementary to the polynucleotide; (b) separating the fluorescently labeled extended oligonucleotide primers based upon their sizes; and (c) detecting the fluorescently labeled extended primers based upon their fluorescence, wherein the fluorescent label of at least one of the fluorescently labeled extended oligonucleotide primers is an energy transfer dye that comprises: (i) a xanthene donor dye capable of absorbing light at a first wavelength and emitting excitation energy in response thereto; (ii) a 4,7-dichlororhodamine acceptor dye capable of absorbing the excitation energy emitted by the donor dye and fluorescing at a second wavelength in response thereto; and (iii) a non-nucleosidic linker linking the xanthene donor dye to the 4,7-dichlororhodamine acceptor dye.