US Patent 10392557 Multi-dye microparticles

The stable and precise incorporation of multiple fluorescent dyes into hydrogel microparticles. The multiple fluorescent dyes, excited with the same source, have distinct fluorescence emission spectra to enable identification of the microparticles. The fluorescent molecules are directly polymerized into the hydrogel matrix or stably incorporated through molecular entanglement. By changing the molar ratios of the fluorescent dyes, different and identifiable microparticles can be synthesized.