The invention discloses a method for purifying an
antibody by using high-density
protein A coated magnetic beads. The method comprises the following steps: adding magnetic beads and an expression product containing the
antibody into a reaction vessel, applying a
magnetic field to the outside or inside of the reaction vessel, and then, transferring out a supernatant; adding a washing
buffer solution into the reaction vessel, and removing the
magnetic field; repeatedly washing the magnetic beads for 2-4 times; adding an eluting
buffer solution, removing the
magnetic field, and incubating for 5-15 minutes at
room temperature; enabling the magnetic beads to be attached to the wall through applying the magnetic field, transferring out the solution, and adjusting the pH value of the solution to be neutral, thereby obtaining a purified
antibody. According to the method, antibody purification is carried out by using a
magnetic bead affinity
separation technology, so that the antibody capture speed is higher compared with that of the traditional
antibody affinity chromatography; in addition, the purifying operation has no need of complicated
chromatography systems, and samples have no need of clarifying treatment, so that the samples with relatively high
viscosity can be directly subjected to purifying operation; moreover, the unique
protein A coated magnetic beads are used, so that the antibody
binding efficiency is increased greatly, and the shedding rate of a
protein A ligand reaches a very low level.