Ligands with a variety of functionalities, including fluorescent labels, affinity tags and solid phase attachment abilities. The ligands form covalent bonds rapidly under general physiological conditions; the bonds are highly specific and essentially irreversible. HaloTag® Fluorescent Ligands enable you to add the chloroalkane group, with which HaloTag® protein reacts, to any compound or surface with a compatible chemical group. The possible applications are endless.
The Alexa Fluor® 488 Ligand is impermeable to cell membranes and, therefore, used to label cell surface proteins. The TMR Ligand, Oregon Green® Ligand, diAcFAM Ligand and Coumarin Ligand readily cross the cell membrane and, therefore, can be used to label intracellular proteins.
HaloTag® Fluorescent Ligands for Cellular Imaging
Cell-permeant ligands (rapid labeling protocol):
- HaloTag® TMR Ligand (555Ex/585Em)
- HaloTag® Oregon Green® Ligand (496Ex/516Em)
- HaloTag® diAcFAM Ligand (494Ex/526Em)
- HaloTag® Coumarin Ligand (353Ex/434Em)
Cell-permeant ligands ("no wash" protocol):
Cell-impermeant ligands for cell-surface labeling (rapid labeling protocol):
- HaloTag® Alexa Fluor® 488 Ligand (494Ex/517Em)
- HaloTag® Alexa Fluor® 660 Ligand (663Ex/690Em)
HaloTag® Ligands for Protein Detection
- HaloTag® Biotin Ligand. Contains a 12-atom linker arm to biotin and is used as an affinity tag to capture the HaloTag® protein-based fusion construct via biotin-streptavidin interaction.
- HaloTag® PEG-Biotin Ligand. Contains a spacer not found in the HaloTag® Biotin Ligand that provides a significantly longer, more flexible linker between streptavidin and the HaloTag® protein. This linker may help preserve HaloTag® fusion partner protein activity upon immobilization or derivatization.
Applications
- Pull Down Protein Complexes: The spacer and reactive linker of the HaloTag® PEG-Biotin Ligand provide ideal pull-down capabilities. Alternatively, pull down directly with the HaloLink™ Resin.
- Image Fixed Cells: The covalent bond is stable, allowing imaging of fixed cells and analysis of the labeled protein under stringent conditions.
- Introduce Novel Functionalities or Perform Sequential Labeling: The open architecture of the technology enables the use of different ligands for multiple applications.
- Design Only One Genetic Construct for Multiple Experiments: Obtain new functionality by using a different HaloTag® Ligand without having to design and clone a new expression construct.
- Analyze Labeled Fusion Proteins Using SDS-PAGE, Mass Spectrometry, etc.: The bound ligand is stable under denaturing conditions.
For more information, see the Protocols & Applications Guide.