... and is cost effective for high volume users In general, Ni2+is the preferred metal ion for purification of histidine-tagged ... group has then been charged with nickel (Ni2+) ions.Ni Sepharose CL-4B has low Ni2+leakage, high protein-binding capacity, and ... -tagged protein/ml medium Metal ion capacity Approx. 15 µmol Ni2+/ml medium Average particle size 90 µm Recommended flow rate ...