A red fluorescent protein, DsRed, which emits fluorescence in the red region of the spectrum has become a popular alternative
to green fluorescent protein as a label in biochemical and bioanalytical applications. In this study, we have developed a
simple purification method for DsRed variants utilizing their inherent copper binding property. A purification procedure was
developed and optimized using immobilized copper ions yielding a single strong band corresponding to purified DsRed proteins
on the SDS-PAGE gel. A purification efficiency of higher than 95% was achieved. A spectral analysis and copper binding study
was performed to verify activity of the purified proteins. The development of this method allows DsRed to play a dual role
as a fluorescent reporter protein and as a purification affinity tag for a target protein. This simpler approach of purification
should expand the utility of DsRed.
Keywords Affinity chromatography - Purification - DsRed