Affinity Reagents

Novel Binding Protein for HaloTag Fusion Protein Studies

Analyze HaloTag fusion proteins in a tube

HaloTag®* is a modified variant of the bacterial haloalkane dehalogenase enzyme from Rhodococcus rhodochrous. It is designed to form a covalent bond with reactive chloroalkane-based ligands. When fused to a protein target of interest this specialized reactive site enables a variety of biochemical and cellular experiments, e.g. sub-cellular localization, enzymatic assays, etc.


One important aspect for biochemical analysis is obtaining ultra-pure HaloTag proteins directly from the cells expressing this construct. The Halo-Trap is a high quality HaloTag binding protein coupled to agarose beads for ultra-high affinity purification of HaloTag fusion proteins and their interacting partners. With the Halo-Trap it is possible to immunoprecipitate HaloTag-fusion proteins even when covalently bound to HaloTag ligands (such as fluorescent dyes). The HaloTag fusion proteins can even be eluted without a protease! This versatile affinity reagent is compatible with immunoprecipitations, Co-IP, mass spectroscopy, and enzyme activity measurements.



Other Nanobody-Trap Reagents
Live Cell Imaging Systems





HaloTag Western Blot

Halo-Trap allows both cellular imaging and biochemical purification

Input (I), non-bound (FT), and bound (B) fractions were separated by SDS-PAGE followed by Coomassie blue staining, Western blotting, and fluorescence scan. Because the Halo-Trap binds to HaloTag at an epitope outside its catalytic center, both unbound HaloTag fusion proteins (left) and HaloTag fusions covalently bound to ligands like HaloTag TMR (right) are captured with similar efficiencies. Such ultra-efficient, 1-step, purification from cells makes both imaging and purification possible. Now cells that are treated with HaloTag ligands for imaging can also be purified for biochemical studies—making the HaloTag system as versatile as GFP-Trap system is for GFP expression.



















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.






Halo-Trap A

anti-HaloTag VHH coupled to agarose beads

Part Numbers
OTA010, OTA020, OTA100, OTA200, OTA400, OTAK020

Halo-binding Protein

Uncoupled and purified HaloTag Binding Protein

Part Numbers

Particle Size:


Halo-Trap A

~90 µm when coupled to an agarose beads

Halo-binding Protein

No particle coupled

Storage Buffer:  

Halo-Trap A

20% EtOH

Halo-binding Protein

1x PBS; Preservative: 0.09% Sodium Azide

Storage and Stability:


Halo-Trap A

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

Halo-binding Protein

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


*HaloTag Trademark owned by Promega Corp


HaloTag Traps

ORDERING - Halo-Traps Coupled to Agarose



Binding Controls
Spin Columns for agarose beads