Ligands for Super Resolution Microscopy
The brightness of fluorescent HaloTag® Ligands means you can examine the expression of your HaloTag® fusion protein inside living cells.
Fluorescent Live Cell Imaging in Single Cells
Super resolution microscopy is a technique where fluorescent probes can be used to resolve detail inside the cells down to the level of molecules like proteins. This means you can visualize where inside the cell molecules labeled with a fluorescent probe are located and observe their interactions. This ability to peer inside living cells and see proteins associated with subcellular structures and organelles offers a method to gain insight into the biological role of a specific protein tagged with a fluorescent probe. HaloTag® technology offers a way to covalently tag a protein of interest with a bright fluorescent dye to better understand how the protein functions in live cells.
Characterize HaloTag® Fusions Inside Live Cells
The tools needed for super resolution microscopy include the bright Janelia Fluor® 549 and Janelia Fluor® 646 HaloTag® Ligands, your HaloTag fusion protein expressed inside cells and an optical microscope. The Janelia Fluor® 549 HaloTag® Ligand and Janelia Fluor® 646 HaloTag® ligands enable characterization of HaloTag® fusions in endogenous cellular settings. Once covalently bonded to the HaloTag® fusion protein, the enhanced brightness of the ligand dyes means you can detect and study single molecules in live cells via 1) Fluorescence Activated Cell Sorting (FACS); 2) Standard confocal imaging; and, 3) In-gel detection with a fluoroimager.
The single-use Janelia Fluor® HaloTag® ligands for high-resolution live-cell imaging enable:
- Single-molecule labeling
- Rapid cell labeling
- High signal-to-noise ratio and specificity
Use the Janelia Fluor® ligands for applications such as FACS, super resolution microscopy, STED microscopy and live-cell microscopy.
Janelia Fluor® Products
Parental U2OS cells and U2OS cells expressing HaloTag® containing a nuclear localization sequence were adhered to glass-bottom chamber slides and labeled with 200nM Janelia Fluor® 646 HaloTag® Ligand for 15 minutes. Cells were imaged with 637nm laser excitation for Janelia Fluor® 646 HaloTag® Ligand. In HaloTag-expressing cells, labeling is restricted to the nucleus. Parental cells (live control in figure) show no labeling. The top row of this set of images is fluorescent signal only. The bottom row shows transmitted images collected at the same respective laser excitation with the fluorescence images overlaid. Images were collected using a Nikon Eclipse Ti confocal microscope equipped with NIS Elements software and a 40X plan fluor oil immersion objective.
Additional HaloTag® Resources
Choosing a Self-Labeling Protein for Confocal and STED Microscopy
SNAP tags and HaloTag® labeling for super resolution microscopy are compared in this Cell Chemical Biology article.
Quantifying Binding at the Single-Molecule Level
This Methods article quantifies transcription factor binding dynamics in live cells using Janelia Fluor® HaloTag® Ligands.
Imaging Dynamic Low-Complexity Domain Interactions
Research published in Science found live-cell imaging provided new insights into the role of low complexity domains in gene regulation.