Immobilized metal ion affinity chromatography (IMAC) is widely used for the purification of many different
His6-tagged recombinant proteins. On the one hand, it is a powerful technique but on the other
hand it has its disadvantages. In this report, we present the development of a unique ssDNA aptamer
for the purification of His3-tagged recombinant proteins. Our study shows that stability of the His3-
tag/H3T aptamer complex can be controlled by the sodium ion concentration. Based on this feature, we
demonstrate that H3T aptamer resin was successfully employed for the purification of three out of four
tested His3-tagged recombinant proteins from an E. coli total protein extract using imidazole-free buffers.
Finally, we show that the purity of His3-tagged proteins is superior when purified with the help of the
H3T aptamer in comparison with Ni-NTA resin.