G-Biosciences' Cobalt Chelating Resin is an immobilized metal affinity chromatography (IMAC) resin that was specifically designed to utilize Co²⁺ for the purification of proteins that associate with Cobalt ions (cobalt binding proteins), including 6x histidine tagged proteins

G-Biosciences' Cobalt Chelating Resin binds to six histidine residues (6x His), a common tag used in protein purification. The resin consists of iminodiacetate coupled to 6% cross-linked agarose beads. The iminodiacetate binds divalent cobalt ion with a capacity of 20-40μmoles Co2+/mL resin. The protein binding capacity is >50 mg protein per ml resin. We have demonstrated binding of >100 mg of a 50 kDa 6X His tagged proteins to a ml of resin. The spin columns are supplied with a resin bed volume of 0.2, 1 and 3 mL with total column volumes of 1, 8 and 22 mL respectively. Columns can be used as a spin format of gravity flow columns.

G-Biosciences' Immobilized Nickel, Copper and Zinc Chelating Resins are also available. Cobalt has the highest selectivity followed by Zinc, Nickel then Copper, but has the lowest loading capacity. Copper has the highest loading capacity, followed by Nickel then Zinc. The capacity of Cobalt is >50 mg per mL. Specific binding/wash and elution buffers are available.

Although 6 X His tagged proteins bind with a slightly lower efficiency compared to Nickel Chelating Resin there is a significant reduction in non-specific binding. Cobalt resins have a higher selectivity for poly-His sequences, however have a low loading capacity, therefore Cobalt Chelating Resin should be used for valuable recombinant proteins in limited quantities.