Activated allophycocyanin is easily conjugated with antibodies and other proteins without the need for chemical cross-linkers. These highly purified allophycocyanin retain their spectral characteristics after conjugation. The activated allophycocyanin is treated with succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC), which reacts with the lysine residues, allowing the maleimide groups to react with the free thiols of the conjugate partner protein. They are ready-to-use and can be directly conjugated without further pre-processing when mixed with thiol-containing targets.
