Product Selection Guide for Immunoprecipitation
| Dynabeads® act as a solid-phase with rapid liquid-phase kinetics, perfect for high-quality immunoprecipitation (IP) procedures. When placed on a magnet, the beads will quickly and gently migrate to the tube wall, allowing for quick buffer exchange and washing. |
Dynabeads®, Kits & Magnets
| Magnets & Mixers:
|
Immunoprecipitation (IP) & Co-Immunoprecipitation (Co-IP)
| Bead Surface non-specific Binding | Antibody (Ab) Coupling Characteristics | Dynabeads Surface Coating | Select Your Product Format | |||
|---|---|---|---|---|---|---|
| Species Compatibility for source antibodies | Are antibodies covalently coupled to bead surface? | Are purified antibodies required? | Coupling Reaction Time | |||
| Low | see table below | no* | no | 10 min | Protein A | Beads only |
| IP KIT | ||||||
| Protein G (top seller) | Beads Only | |||||
| IP KIT | ||||||
| Low | Mouse | no | no | 30 min | Sheep α-Mouse | Beads Only |
| Rabbit | no | no | 30 min | Sheep α-Rabbit | Beads Only | |
| Ultra Low | Any | Yes | no | overnight | Epoxy (top seller) | Beads Only |
| Antibody Coupling KIT | ||||||
| Co-IP KIT | ||||||
* Antibodies can be covalently linked onto Protein A & G Dynabeads using commercially available crosslinkers.
Benefits of crosslinking include covalently locking antibodies onto the bead surface such that they do not co-elute with immunoprecipitated target proteins during the final elution step. This will enable you to run a gel without having the antibody heavy and light chains co-migrating with immunoprecipitated proteins. Anytime that you crosslink antibodies using crosslinking reagents there is a significantly increased risk of dramatically reducing the yield of the immunoprecipitation while simultaneously decreasing the antibodies specificity to its target(s). The end result of crosslinking will likely be increased non-specific antibody-ligand binding and reduced capacity.
For covalent antibody coupling to Dynabeads, we therefore recommend Dynabeads® Tosylactivated and Dynabeads® M-270 Epoxy (now available with all buffers required for antibody coupling as the Dynabeads® Antibody Coupling Kit: also linked in the table above). These beads and kits provide all of the upsides of covalent antibody coupling to beads without any of the potential pitfalls that crosslinking can introduce.
Antibody Compatibility Table: Dynabeads® Protein A & Dynabeads® Protein G
+++: strong binding, ++: medium binding, +: weak binding, -: no binding.
| Species | Ig Subclass | Protein A | Protein G |
|---|---|---|---|
| Human | IgG1, IgG2, IgG4 IgG3 IgD IgD Fab ScFv | +++ + - + + + | +++ +++ - - + - |
| Mouse | IgG1 IgG2a, IgG2b, IgG3 IgM | + +++ - | ++ +++ - |
| Rat | IgG1 IgG2a IgG2b IgG2c | + - - +++ | ++ +++ + +++ |
| Goat | IgG1 IgG2 | + +++ | +++ +++ |
| Sheep | IgG1 IgG2 | + +++ | +++ +++ |
| Cow / Bovine | IgG1 IgG2 | + +++ | +++ +++ |
| Horse | IgG(ab) IgG(c) IgG(T) | + + - | - - +++ |
| Rabbit | Total Ig | +++ | +++ |
| Dog | Total Ig | +++ | + |
| Cat | Total Ig | +++ | + |
| Pig | Total Ig | +++ | + |
| Guinea pig | Total Ig | +++ | + |
| Chicken | Total Ig | - | - |
Protein G and protein A exhibit variation in binding strengh to different Immunoglobulins (Ig). This variation exists both between different species and between different antibody subclasses from the same species. (As an example, human IgG3 will bind strongly to protein G, but only weakly to protein A.) The table above gives an overview of binding strengths of protein G and protein A to different Ig species and subclasses.
For Igs with weak affinity to both protein A and protein G (or for Ig subclasses not specified in the table above, we recommend the Dynabeads® Antibody Coupling Kit which is compatible with all antibody species and subclasses.
