A method is provided for genotyping a target sequence at at least two allelic sites by a 5′ nuclease amplification reaction. In one embodiment, the method includes performing a nucleic acid amplification on a target sequence having at least two different allelic sites using a nucleic acid polymerase having 5′→3′ nuclease activity and a primer capable of hybridizing to the target sequence in the presence of two or more sets of allelic oligonucleotide probes wherein: each set of allelic oligonucleotide probes is for detecting a different allelic site of the target sequence, each set of allelic oligonucleotide probes includes two or more probes which are complementary to different allelic variants at the allelic site being detected by the set of probes, the allelic site being 5′ relative to a sequence to which the primer hybridizes to the target sequence, and at least all but one of the allelic oligonucleotide probes include a different fluorescer than the other probes and a quencher positioned on the probe to quench the fluorescence of the fluorescer; detecting a fluorescence spectrum of the amplification;calculating a fluorescence contribution of each fluorescer to the fluorescence spectrum; anddetermining a presence or absence of the different allelic variants at the two or more different allelic sites based on the fluorescence contribution of each fluorescer to the combined fluorescence spectrum.