Patent ID: 6838289

Claim:
A particle comprising: a) a fluorescent analyte detection dye, the analyte detection dye being capable of being excited by light at a first excitation wavelength and capable of emitting light at a maximum wavelength when excited, and b) two or more than two fluorescent labels in a first combination of relative amounts, the fluorescent labels being capable of being excited by light of a same second excitation wavelength and capable of emitting lights at maximum wavelengths, distinguishable from each other, respectively, wherein the maximum wavelength of the emitted light of the analyte detection dye is different from the first and second maximum wavelengths of the emitted lights of the fluorescent labels by at least 100 nm, and the first and second excitation wavelengths differ by at least 100 nm and one of the excitation wavelengths is greater than about 750 nm.