Ni NTA Magarose Beads can be used to purify 6xHis-tagged proteins expressed in series of expression vectors, such as E.coli., yeast, insect cells and mammalian cells. The chelating group has then been charged with nickel ions (Ni2+). This form is very stable octahedral structure of nickel ions in the center, which can protect the nickel ions from attack of the competitive small molecule. The structure of Ni-NTA is compatible with a certain concentration of reducing agents, denaturing agents, detergents and other additives.