Affinity Reagents

Novel Antibody Fragment that binds GFP Fusion Proteins

Analyze GFP fusion proteins – in a tube

Chimeric proteins containing naturally-evolved fluorescent proteins are popular tools to study protein localization and dynamics using microscopy. These constructs usually fuse the entire, or at least a functional domain, of a target protein to one of the multitude of fluorescent proteins. Those originally derived from the jellyfish A. victoria are referred to as green fluorescent protein or GFP. Cellular analysis of the GFP-fusion protein construct is easily accomplished with a host of available live cell imaging solutions. However - to get the full picture - such data have to be combined with additional biochemical information for the respective target proteins, typically fused to a different “tag” domain that allows for purification. These additional in vitro analyses can be used to confirm functionality of the “tagged” fusion construct, as well as to pull out multi-protein complexes that may form in the cellular milieu. So far, the lack of specific, reliable, and efficient reagents has limited the possibility to combine the cell biology results with direct biochemical analysis. Until now, that is.





White Paper
GFP-Trap References
Application Notes
Other Nanobody-Traps
Nano-Booster Fluorescence  Enhancers
GFP & RFP Antibodies
Live Cell Imaging Systems


GFP-Traps utilize super-high affinity Camelidae antibody fragments coupled to agarose beads or magnetic agarose beads. These “Nanobody-Traps” are perfect for immuno-precipitation, immuno-purification and immuno-pull down experiments with up to 10-fold better purity and yield than that of classic mouse monoclonal antibodies. Compatible with a variety of source materials, Nanobody-Traps may be used with mammalian cells, tissues & organs, bacteria, yeast and even plants. These reagents allow your GFP-fusions to be perfect candidates for immunoprecipitations, Co-IP, mass spectroscopy, enzyme activity measurements, and ChIP analysis.




GFP-Trap Affinity Reagents are perfect for fast, clean and efficient one-step isolation of these fluorescent fusion proteins and their interacting factors. With eight years of production experience and over 1000 publications attesting to their broad use and effectiveness, we invite you to try this unique reagent for free. They've become a staple of cell biology research from Europe to North America. The GFP-Traps not only are offered bound to beads or particles, but also attached to the bottom of a 96-well plate, and even as a free complex, providing you the ability to maximize their use.


GFP-Trap Comparison

Nanobody-Traps allow GFP to be used as affinity tags

GFP proteins are not traditionally considered as affinity tags to purify fusion proteins. Nanobody-Traps have changed this notion. To the left is a comparison of GFP-Trap with conventional monoclonal and polyclonal antibodies. Immunoprecipitations (IP) of GFP from protein extracts of GFP-producing human cells was performed. Input (I), non-bound (FT) and bound (B) fractions were separated by SDS-PAGE followed by Coomassie staining and Western Blotting. (hc) heavy chain, (lc) light chain of conventional antibodies. The GFP-Trap protocol took 1/10th the time of traditional antibody-based immunoprecipitation, with better purity, and resulted in 10-fold higher recovery as indicated by western analysis.











GFP-Trap Comparison 2

Protein complexes can’t hide from Nanobody-Traps

To the right are results from using GFP-Trap bound to magnetic particles (GFP-Trap M) and agarose beads (GFP-Trap A). Comparison of GFP-Trap A and GFP-Trap M was first performed with a simple, 1-step, pull-down of native GFP with GFP-Trap A and GFP-Trap M from 293T cell extracts. Input (I) and bound (B) fractions were separated by SDS-PAGE followed by Coomassie staining. As expected, the bound fractions containing GFP are extraordinarily pure. The same 1-step purification procedure was now applied to GFP fused to the protein PCNA in a co-immunoprecipitation type experiment. This time, the chimera and any associated proteins were very efficiently purified with both GFP-Trap A and GFP-Trap M from 293T cell extracts. As can be seen for the gel, the additional bands represent potential binding partners for the GFP-PCNA.




What’s your lab’s favorite flavor?

Nanobody-Traps are high quality binding proteins coupled to a monovalent matrix (agarose beads, magnetic particles or in 96-well plates) for biochemical analysis of many fusion proteins and their interacting partners. The different formats allow you to perform a multitude of experiments. The most popular forms are when the Nanobody-Traps are linked to agarose beads. Agarose beads provide the largest binding capacity and lowest background, while still being easy to work with. If automation is important to your lab, then magnetic particles and magnetic agarose particles are a great choice. The magnetic particles are smaller and easier to keep in suspension, while the magnetic agarose particles offer the superior binding kinetics. For high throughput, nothing beats the 96-well plate in which the Nanobodies are bound to the side of the wells. These resins can be used interchangeably for pull-down type experiments such as immunoprecipitations, co-IPs and even ChIP assays. The purified protein complexes are compatible with down-stream analyses such as mass spectroscopy.


Camelidae Antibody

Camelidae single-domain antibodies are like IgGs on steroids

The family of animals known as Camelidae (camels, dromedaries, llamas, and alpacas) produce functional antibodies devoid of light chains, so called "heavy chain" antibodies. Heavy chain antibodies recognize and bind their antigens via a single variable domain. When cleaved from their carboxy tail, these barrel-shaped structures (2x3 nm) are extraordinarily small, naturally-occurring, and intact antigen binding fragments (MW of 13 kDa). Called “Nanobodies”, these proteins are characterized by high specificity, affinities in the low nanomolar range, and dissociation constants in the sub-nanomolar range (typically 10- to 100-fold better than mouse IgGs). The compact size of Nanobodies makes them extremely stable at temperatures up to 70°C, and functional even in 2M NaCl or 0.5% SDS. These small and powerful antibody fragments can be used in a variety of unique applications. They will open up your research possibilities.


Application notes:


GFP-Trap for ChIP


Chromatin Immunoprecipitation (ChIP) Protocol for A. thaliana 


GFP-Trap for enzyme assays 


GFP-multiTrap for Sandwich ELISA to quantify the expression levels of  fusion proteins in cellular extracts


GFP-Trap capture surface for Biacore™ assays 





GFP-Trap A

Specific Camelidae antibody linked to agarose bead

Part Numbers
GTA010, GTA020, GTA100, GTA200, GTA400, GTAK020


Specific Camelidae antibody linked to magnetic agarose particle

Part Numbers
GTMA010, GTMA020, GTMA100, GTMA200, GTA400, GTMAK020


Uncoupled and purified Camelidae antibody

Part Numbers




GFP, eGFP, wtGFP, GFP S65T, TagGFP, AcGFP, eYFP, YFP, Venus, Citrine, eCitrine, CFP

(does not recognize TurboGFP or all RFPs)

Binding Capacity:


GFP-Trap A

10µl binds 3-4µg of recombinant GFP/RFP


10µl binds 3-4µg of recombinant GFP/RFP

Particle Size:


GFP-Trap A

~90 µm  


~40 µm


No particle coupled

Storage Buffer:  

GFP-Trap A

20% EtOH


20% EtOH


1x PBS; Preservative: 0.01% Sodium Azide

Storage and Stability:


GFP-Trap A

store at 4°C; stable for one year. Do not freeze.


store at 4°C; stable for one year. Do not freeze.


store at 4°C; stable for one year. Do not freeze.

GFP Traps Coupled to Agarose Beads

ORDERING - GFP-Traps Coupled to Agarose



GFP Traps Coupled to Magnetic Agarose Beads

ORDERING - GFP-Traps Coupled to Magnetic Agarose Beads




GFP Traps Non-Coupled

ORDERING - GFP-Traps Non-Coupled


Binding Controls



Protein Controls



Spin Columns