Ni-Coated Plate

https://bmcbiotechnol.biomedcentral.com/articles/10.1186/1472-6750-8-16

Preparation of Ni2+-NTA coated microtiter plates The Ni2+-NTA coated microtiter plate was prepared as described previously  except an ordinary ELISA carboxylated polystyrene microplate (polystyrene high BIND microplate, Corning life science, USA) was used instead of a plate coated with maleic anhydride (Pierce, USA) as the later is 20 times more expensive.

Briefly, a microtiter plate was coated with N,N-bis [carboxymethy]lysine (Sigma Aldrich, USA) overnight and washed 3 times with 0.05% Tween 20 before blocking with 3% BSA in 50 mM Tris-HCl, pH 7.5, 150 mM NaCl, 0.05% Tween 20. The coated plate was washed with a series of buffers including 1) 50 mM Tris-HCl, pH 7.5, 500 mM imidazole, 0.05% Tween 20 2) 0.05% Tween 20 3) 100 mM EDTA, pH 8.0 and 4) 0.05% Tween before charging with 10 mM NiSO4 for 20 minutes at room temperature. After washing with 0.05% Tween 20 and then with 50 mM Tris HCl, 500 mM NaCl, pH 7.5, the plate was then ready to be used to capture (His)6-containing proteins.