Immunoprecipitation / IP-Heavy chain & light chain

Problem & Solution

1. When running the IP purified protein on a western blot, there are two extra bands. Is this the antibody eluting with the protein? How can this be avoided?

To enable elution of target protein with less antibody contamination (for cleaner protein preparation and cleaner western blots), it is recommended to cross link the antibody to the beads. The target protein should then be eluted with a mild eluent, such as Polypeptide solution.

2. My protein of interest migrates in the vicinity of IgG heavy chain, how can I detect my immunoprecipitated protein without interference from the IgG signal?

To eliminate the interfering of IgG signals when westerns are performed on samples immunoprecipitated with secondary antibody which just bind natural antibody.
Besides ,if the target protein is tagged by a tag ,you also can choose the Sino Biological tag antibody immunomagnetic beads, which there is much less disturbance of heavy chain and light chain.