The Mouse anti-HIS immunomagnetic beads, conjugated with Anti-HIS mouse monoclonal antibody, are used for immuneprecipitation (IP) of HIS-tagged proteins expressed in vitro expression systems. For IP, the Immunomagnetic beads are added to a sample containing HIS-tagged proteins to form an Immunomagnetic Beads-protein complex. The complex is removed from the solution manually against a Magnetic separation device. The bound HIS-tagged proteins are dissociated from the Immunomagnetic beads using an Elution Buffer.