Ni-NTA Magnetic Beads are used for small scale affinity purification as well as high-throughput screening of recombinant His-tagged proteins. The polyhistidine tag is the most popular affinity tag and typically consists of six consecutive histidine residues (6xHis). These tagged proteins are overexpressed in a number of different systems, most commonly in bacteria, and purified from cell lysates. Purification of His-tagged proteins is achieved using a NTA chelate charged with nickel that coordinates with the histidine side chains. The NTA chelate contains four metal-binding sites which allow for low metal ion leaching and high binding capacity. The protocol for the Ni-NTA Magnetic Beads has been optimized to allow for high purity of the isolated His-tagged protein. Performance is equivalent to or better than Ni-NTA magnetic beads from other suppliers.