BeaverBeads Protein A/G Immunoprecipitation Kit

Product Overview

The BeaverBeads™ Protein A/G Immunoprecipitation Kit supplies 2 µm superparamagnetic microspheres covalently coated with the recombinant Fc-binding domains of both Protein A and Protein G, together with the binding, washing, elution and neutralisation buffers needed to run a complete immunoprecipitation.

Combining both ligands widens species and isotype coverage well beyond either alone. Rat IgG2a and IgG2b, mouse IgG1 and IgG2b, and bovine, goat, sheep and horse IgG all bind Protein A/G strongly while binding Protein A weakly or not at all — so the same kit works across most common host species without changing reagent.

Why the format matters

25 µL of beads per reaction; antibody capture in 15 minutes. The high surface area of micron-scale beads shortens the equilibration time for both antibody capture and antigen binding. In the manufacturer's protocol the antibody adsorption step completes in 15 minutes and antigen precipitation in 10 to 30 minutes, against the hours typical of agarose slurry protocols. Shorter handling means less time for proteases to act on the target, which helps preserve both the activity of the protein and the integrity of any complex it is part of.

Antibody binding by species and isotype

Reproduced from the manufacturer's user manual. Key: +++++ strong, +++ medium, + weak, – no binding.

Sample types and workflow

Validated by the manufacturer for cell lysate, cell culture supernatant, blood plasma, ascites and tissue culture supernatant, with specific pre-treatment protocols given for serum, suspension cells, adherent cells and E. coli. Two elution routes are provided: a denaturing elution into SDS-PAGE loading buffer for gel analysis, and a native elution into low-pH elution buffer followed immediately by neutralisation buffer, which preserves biological activity for downstream functional work. An optional antibody cross-linking step (BS3 or equivalent) allows the antigen to be eluted without the antibody.

Kit contents

Component quantities below are for Cat. 22202-20 (20 reactions): BeaverBeads™ Protein A/G for IP, 1 mL · IP Binding Buffer, 30 mL · PBS 10× (dilute to 1× before use), 20 mL · IP Washing Buffer, 20 mL · IP Elution Buffer, 0.5 mL · IP Neutralization Buffer, 0.2 mL · Magnetic Separator Stand 2/15, optional. The 100-reaction pack (Cat. 22202-100) scales these proportionally.

Handling and safety

Molecular weight caution. A small amount of Protein A/G can shed from the bead surface under extreme conditions such as low-pH elution or heat treatment. The manufacturer advises against using this product to immunoprecipitate a target of approximately 130 kDa, because shed ligand can co-migrate and obscure the band.

A magnetic separator is required. Vortex beads thoroughly before use. Do not freeze or centrifuge the beads — both cause irreversible aggregation. Always transfer beads to a fresh tube before the elution step, so that protein adsorbed non-specifically to the original tube wall is not carried into the eluate. Dilute the 10× PBS under sterile conditions and discard it at any sign of contamination.

For Research Use Only. Not for use in diagnostic or therapeutic procedures. Specifications and protocol are those published by the manufacturer, BEAVER Biomedical Engineering Co., Ltd.