Our Halo-Trap is a high affinity Halo-binding protein coupled to agarose beads for biochemical analysis of Halo fusion proteins and their interacting partners. The Halo is a modified variant of the bacterial haloalkane dehalogenase enzyme from Rhodococcus rhodochrous and is designed to form a covalent bond with reactive chloralkane-based ligands.

 Use Halo-Trap for:

  • Immunoprecipitation (IP) / Co-IP
  • Mass spectrometry
  • Enzyme activity measurements
  • ChIP/ RIP analysis

Very stable & reliable binding

  • high affinity with a very low dissociation constant KD of 2nM
  • harsh washing conditions can be applied
  • recombinant, validated antibody
  • Structure and function are characterized

Halo-protein immunoprecipitated with either Halo-Trap (left) or an alternative supplier's product (right):
Recombinantly expressed Halo-protein bound to Halo-TMR. Input (I), non-bound (FT) and bound (B) fractions were separated by SDS-PAGE followed by Coomassie blue staining, Western blotting and fluorescence scan. Please note, additional bands are visible due to sensitivity of the Halo-protein to SDS. Because the Halo-Trap binds to Halo-tag at an epitope outside its catalytic center, Halo-proteins covalently bound to ligands like Halo-TMR (left) are effectively captured. In contrast, the competitor’s product precipitates no or just minimal amounts of the Halo protein. This allows to pulldown Halo-fusion proteins from cells that have been previously treated with Halo-ligands for imaging and makes the Halo system as versatile as GFP expression, imaging and purification.

Compared to other Halo tools,

  • Halo-Trap precipitates Halo-fusion proteins even when already covalently bound to Halo-ligands, i.e. after labelling etc.
  • Halo-Trap can be used for affinity purification
  • bound Halo-fusion protein can be eluted without protease

Immunoprecipitation and elution of Halo-protein from spiked HEK293T cell lysates:
Input (I), non-bound (FT), eluted (E), residual (R) fractions and protein marker (M) were separated by SDS-PAGE followed by Coomassie blue staining and Western blotting. Elution of Halo-protein with elution buffer (low pH) from Halo-Trap is efficient (left).