Abstract: Ammonium sulphate sedimentation combined with DEAE Sepharose Fast Flow chromatography for B-phycoeryth-rin (B-PE) purification from the red alga Porphyridium cruentum was established in this paper.The rusults showed that after precipitation with 65% saturated ammonium sulphate for two days and purification with chromatography, the purity of B- phycoerythrin reaches A545nm/A280nm=3.0. However after precipitation for two months, the high purity of B-phycoerythrin can be obtained by only one-step chromatography to reach 5.37 and can fulfill the purity standards as 4.5. This suggests that 65% ammonium sulphate has a high selectivity on B-PE. The effect of precipitation process intensely affects influenced the purity of B-phycoerythrin. The absorption spectrum and the fluorescence spectrum of producetion are both in accordance with characteristics of B-phycoerythrin. Native-PAGE showed only one single dark ribbon which means that B-phycoerythrin is homogeneous. SDS-PAGE appeared two ribbons, one is α- and β-subunit with molecular weight about 16～18kD, while the other one is γ-subunit with molecular weight about 31kD. At the same time, capillary electrophoresis and laser induced fluorescence method are both established for fast analysis on B-phycoerythrin purity. The result shows one single peak that means capillary electrophoresis method is highly effective for analysis on purity of B-phycoerythrin.

Key words:  , B-phycoerythrin； DEAE Sepharose F F chromatography； capillary electrophoresis；