I am planning to perform a co-immunoprecipitation experiment using the Pierce His Protein Pull-Down Kit (https://www.thermofisher.com/order/catalog/product/21277). My bait and prey proteins are both previously purified, and my bait protein as an N-terminal His tag. I am trying to determine what the appropriate controls would be to ensure that any interaction I see between and bait and prey is specific. The kit mentions that I should do a "Minus bait, Plus prey" control, which would determine if the prey interacts non-specifically with the beads. They also mentioned a "Plus bait, Minus Prey" control. Are there any other controls I should plan for?