Ni regeneration protocol

1. Wash with 5-10 column volumes of 50 mM EDTA.
2. Wash with 5-10 column volumes of 100 mM sodium hydroxide or 1% SDS.
3. Wash with 20 ml DI water.
4. Recharge column with 3 ml 100 mM nickel sulfate solution.
5. Wash again with DI water.
6. Store in 20% ethanol.