PureCube Co-NTA Agarose
The His tag is the most widely used affinity tag due to its small size, low immunogenicity, and versatility under native or denaturing conditions, as well as in presence of detergents and many other additives. In addition to the widely used Ni-NTA Agarose, Cube Biotech offers high-performance PureCube Co-NTA Agarose, based on BioWorks Workbeads with an average bead size of 40 µm, for purification of his-tagged proteins. Specificity of this transition metal for histidine stretches is typically higher than that of nickel (see Fig. 1). PureCube Co-NTA Agarose is provided as a 50% suspension, and also available as prepacked cartridge. For purification of his-tagged proteins from cell culture supernatants or for pull-down experiments, we recommend PureCube Co-NTA MagBeads. To detect His-tagged proteins in Western Blot experiments, Cube Biotech offers the highly specific PentaHis antibody.
Why PureCube Co-NTA Agarose?
Optimal balance of yield and purity
Superior DTT and EDTA stability
Can be regenerated for reuse
Different metal ions confer different binding affinity and specificity
Loading different metal ions to a resin results in differing affinity and specificity for a his-tagged protein. Generally, cobalt exhibits the higest binding specificity of commonly used IMAC metal ions, leading to relatively low yields but high purity. Copper, at the other end of the spectrum, has a high affinity leading to high yields but unspecific binding. In searching for the optimal resin to purify a protein, it is recommended to explore different chelating ligands (IDA or NTA) and different metal ions.
Fig. 3: Affinity and specificity of metal ions commonly used for IMAC. Loading an IMAC resin with different metal ions can adjust the affinity and specificity to optimize the purity and yield of a purified protein.
Co-NTA Agarose was successfully used in the following publication:
Li, Y. et al. Self-assembly with orthogonal imposed stimuli to impart structure and confer magnetic function to electrodeposited hydrogel. Applied Materials & Interfaces, Published April 29, 2015