B-Phycoerythrin (B-PE), a fluorescent protein from phycobiliprotein family, is isolated from cyanobacteria and eukaryotic algae. SMCC activated B-PE is chemically modified with SMCC. SMCC reacts with the primary amine on B-PE and introduces maleimide groups to B-PE. These maleimide groups easily react with thiol groups of target protein without the need for any additional activation, resulting in convenient conjugation of B-PE with proteins. Its primary absorption peak is at 545 nm with secondary peak at 563 nm. B-PE and the closely related R-PE are the most intensely fluorescent phycobiliproteins having orange fluorescence. They are significantly brighter and more photostable than conventional organic fluorophores. B-PE conjugates have been widely used in applications such as flow cytometry and multi-color immunofluorescent staining.
Chen FT and Pentoney SL Jr (1994). Characterization of digoxigenin-labeled B-phycoerythrin by capillary electrophoresis with laser-induced fluorescence. Application to homogeneous digoxin immunoassay. J Chromatogr A 680, 425-30. Ficner R, et al. (1992). Isolation, crystallization, crystal structure analysis and refinement of B-phycoerythrin from the red alga Porphyridium sordidum at 2.2 ┼ resolution. J Mol Biol 228, 935-50.