Zinc chelates seem to recognize well two exposed histidine tags in vicinal (neighboring) positions. This kit is recommended for proteins that are difficult to separate.
It includes: 2ml of HIGH Density ZINC & 2ml of LOW Density ZINC, so the customer can obtain the best compromise between binding capacity and selectivity/specificity using two different charged resins.
HIGH Density ZINC provides a higher amount of available groups and usually allows for higher binding capacity. LOW Density ZINC has a lower amount of groups and it usually improves the selectivity/specificity.