Magnetic beads labeled protein is a combination of magnetic beads with active proteins . Magnetic beads are used as a protein carrier and can be attracted by the magnetic force of a magnet. When the protein adsorbed on the magnetic beads is combined with the corresponding microorganism or specific antigen substance, an “antigen-antibody-magnetic bead immune complex” is formed. This complex has high magnetic responsiveness. It moves directly under the action of the magnetic force of the magnet to separate the complex from other substances, thereby achieving the purpose of separating, concentrating, and purifying microorganisms or specific antigen substances.