Cloning, expression and two-step purification of recombinant His-tag enhanced green fluorescent protein over-expressed in Escherichia coli.

In this report, we describe a two-step chromatographic procedure for the purification of His-tag EGFP by immobilized metal affinity expanded bed adsorption (IMAEBA) as the capture step and size exclusion chromatography as the polishing step. The use of proteins including a histidine-tag facilitates their subsequent purification after expression in many microorganisms. This meets the needs of scientific researchers as well as industrialists in purifying recombinant proteins. The procedure described allowed the obtention of 230 mg pure EGFP from 1 l simple batch culture with a recovery of 90%.