Abstract:CcmK2,as one of the most abundant carboxysome shell proteins in Synechocystis sp. PCC 6803,plays an important role in the assembly and biogenesis of carboxysome.In this study,the prokaryotic expression vector pET28aCcmK2 was constructed and high yield recombinant CcmK2 protein with six histidine tags was expressed by inducing in Escherichia coli BL21 (DE3).In order to produce the polyclonal antibody against rabbit,the highly performed CcmK2 protein was purified with metal affinity chromatography.Result of Dot blot analysis showed that the polyclonal antibody could effectively detect cyanobacterial CcmK2 protein.Result of antibody specificity test showed that CcmK2 polyclonal antibody could weakly reacted with other carboxysome shell proteins.Western blot analysis confirmed that this antibody was able to specifically and sensitively detect the abundance of CcmK2 in cyanobacterium PCC 6803.The polyclonal antibody generated in this study will lay a foundation for further studying the abundance of CccmK2 in cyanobacterium PCC 6803.