Performing a Purification of IgG Antibodies with Protein G HP MultiTrap™

Protein G HP MultiTrap™ are 96-well plates prepacked with Protein G Sepharose® High Performance. Protein G HP MultiTrap™ is a versatile tool for screening of different proteins and for preparation of protein samples, enrichment of proteins of interest from clarified cell lysates and biological fluids, and small-scale purification of antibodies (Figure 3.6). Purification runs are performed in parallel, which ensures fast and reliable capture of antibodies from a large number of complex samples.

Each pack of Protein G HP MultiTrap™ contains four prepacked multiwell plates and protocols for protein enrichment of target antibody-antigen complexes by immunoprecipitation and for small-scale antibody purification. Collection plates for collecting eluted, purified antibody are available separately.

The procedure for small-scale screening and purification of antibodies is described below. For a description of the immunoprecipitation procedure, download Instructions 28906773.

Protein G HP MultiTrap™ 96-well plates

Figure 3.6. Protein G HP MultiTrap™ 96-well plates are used for rapid, parallel screening and small-scale purification of monoclonal and polyclonal antibodies at small scale.


Sample preparation

Refer to Desalting and buffer exchange for general considerations.

The sample should have a pH around 7.0 before applying to the column. If required, adjust sample conditions to the pH and ionic strength of the binding buffer by either buffer exchange on a desalting column (see Desalting and buffer exchange) or dilution and pH adjustment.


Buffer preparation

Binding buffer: 0.02 M sodium phosphate, pH 7.0

Elution buffer: 0.1 M glycine-HCl, pH 2.7

Neutralizing buffer: 1 M Tris-HCl, pH 9.0

Water and chemicals used for buffer preparation should be of high purity. Filter buffers through a 0.45 µm filter before use.

Buffers can be prepared from the 10× stock solutions of binding and elution buffers supplied with Ab Buffer Kit.



  1. Prepare two collection plates with 15 µl neutralizing buffer per well.

To preserve the activity of acid-labile IgG, we recommend adding 15 µl of 1 M Tris-HCl pH 9.0 to collection wells in the collection plate, which ensures that the final pH of the sample will be approximately neutral.

  1. Invert and gently shake the MultiTrap™ plate to resuspend the medium. Remove top and bottom seals and place the MultiTrap™ plate on a collection plate. Centrifuge for 1 min at 70 to 100 × g to remove the storage solution.
  2. Equilibrate by adding 300 µl binding buffer. Centrifuge for 30 s at 70 to 100 × g.
  3. Bind antibody by adding maximum 300 µl of the antibody sample. Incubate for 4 min while gently mixing. Centrifuge for 30 s at 70 to 100 × g.
  4. Wash by adding 300 µl binding buffer and centrifuge for 30 s at 70 to 100 × g. Repeat this step.
  5. Replace the collection plate with a fresh collection plate prepared in step 1.
  6. Add 200 µl of elution buffer to elute the antibody and centrifuge for 30 s at 70 × g. Collect the eluate. Repeat this step. Most of the bound antibody is eluted after two elution steps.

Desalt and/or transfer purified IgG fractions to a suitable buffer using a desalting column (see Desalting and buffer exchange).



Store in 20% ethanol at 2°C to 8°C.


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