Self-labeling Tags
Self-labeling tags are protein tags used to attach various molecules to a protein of interest (POI). They are genetically encoded proteins that can be co-expressed with a POI to generate a tag-POI fusion protein. The tag-fusion protein can then be labeled with a ligand of choice such as a fluorescent dye, enabling live cell imaging of the POI by fluorescence microscopy.
| Cat. No. | Product Name / Activity |
|---|---|
| 8817 | CoraFluor™ 1, Haloalkane New |
| Cell impermeable terbium cryptate FRET donor for TR-FRET assay development, with chloroalkane ligand | |
| 8818 | CoraFluor™ 2, Haloalkane New |
| Cell permeable terbium cryptate FRET donor for TR-FRET assay development, with chloroalkane ligand | |
| 8102 | dTAG Janelia Fluor® 525 |
| Fluorogenic srTAG probe for live cell imaging of FBKP12 (F36V/L) fusion proteins | |
| 8103 | dTAG Janelia Fluor® 585 |
| Fluorogenic srTAG probe for live cell imaging of FKBP12(F36V/L) fusion proteins | |
| 8101 | dTAG Janelia Fluor® 635 |
| Fluorogenic srTAG probe for live cell imaging of FBKP12 (F36V/L) fusion proteins | |
| 8805 | Janelia Fluor® 525, Haloalkane |
| Cell-permeable fluorogenic fluorescent dye with a chloroalkane handle. Application: live-cell imaging as a self-labeling tag substrate | |
| 8806 | Janelia Fluor® 549, Haloalkane |
| Cell-permeable fluorogenic fluorescent dye with a chloroalkane handle. Application: live-cell imaging as a self-labeling tag substrate | |
| 8807 | Janelia Fluor® 585, Haloalkane |
| Cell-permeable fluorogenic fluorescent dye with a chloroalkane handle. Application: live-cell imaging as a self-labeling tag substrate | |
| 8808 | Janelia Fluor® 635, Haloalkane |
| Cell-permeable fluorogenic fluorescent dye with a chloroalkane handle. Application: live-cell imaging as a self-labeling tag substrate | |
| 8809 | Janelia Fluor® 646, Haloalkane |
| Cell-permeable fluorogenic fluorescent dye with a chloroalkane handle. Application: live-cell imaging as a self-labeling tag substrate | |
| 8815 | PA Janelia Fluor® 646, Haloalkane |
| Photoactivatable Janelia Fluor® 646 with chloroalkane handle for self-labeling tags fusion protein |
Self-labeling tags are protein tags used to attach various molecules to a protein of interest (POI). They are genetically encoded proteins that can be co-expressed with a POI to generate a tag-POI fusion protein. The tag-fusion protein can then be labeled with a ligand of choice such as a fluorescent dye, enabling live cell imaging of the POI by fluorescence microscopy (figure 1).
Self-labeling Tag systems offer several advantages:
- can be used for fixed and live cell imaging
- allows use of different fluorophores
- suitable for confocal imaging, super-resolution microscopy (SRM) or TR-FRET
- higher brightness and photostability
Figure 1: Illustration of self-labeling Tag protein (HaloTag®, SNAP-tag® or dTAG) fused to a protein of interest (POI) labeled with a fluorogenic dye ligand.
Tocris offers two categories of fluorogenic dye ligands for live cell imaging of self-labeling tags: Janelia Fluor® Haloalkanes and dTAG Janelia Fluor®.
HaloTag is a trademark of Promega Corporation, and SNAP-tag is a trademark of New England BioLabs, Inc.
Janelia Fluor is a registered trademark of Howard Hughes Medical Institute.
Janelia Fluor® Haloalkanes
The Janelia Fluor® Haloalkane dyes are cell-permeable fluorogenic dyes with a chloroalkane handle. They covalently bind to HaloTag® self-labeling protein which can be used for tagging a protein of interest. Several of these dyes show a high degree of fluorogenicity following binding to the HaloTag protein, enabling wash-free imaging. They are suitable for use in live-cells, tissues and in vivo imaging, and are especially well suited to super-resolution microscopy (SRM) techniques.
| Cat. No. | Product Name | Activity | Emission Color | λex (nm) | λem (nm) | Application |
|---|---|---|---|---|---|---|
| 8805 | Janelia Fluor® 525, Haloalkane | Cell-permeable fluorogenic fluorescent dyes with a chloroalkane handle | Yellow | 525 | 549 | Confocal microscopy, SRM |
| 8806 | Janelia Fluor® 549, Haloalkane | Yellow | 549 | 571 | ||
| 8807 | Janelia Fluor® 585, Haloalkane | Orange | 585 | 609 | ||
| 8808 | Janelia Fluor® 635, Haloalkane | Red | 635 | 652 | ||
| 8809 | Janelia Fluor® 646, Haloalkane | Red | 646 | 664 | ||
| 8815 | PA Janelia Fluor® 646, Haloalkane | Red | 646 | 664 |
Table 1: Summary of spectral data and imaging applications for Janelia Fluor® Haloalkane probes.
dTAG Janelia Fluor®
dTAG Janelia Fluor® probes are fluorogenic self-renewable tag (srTAG) probes for live cell imaging of transiently expressed FKBP12F36V/L fusion proteins. dTAG Janelia Fluor® probes bind the srTAG non-covalently and can therefore spontaneously recover the fluorescence signal after photobleaching, which allows 2-6 times longer imaging duration compared to commonly used self-labeling tags. dTAG Janelia Fluor® probes are compatible with SRM including STED microscopy and can be combined with other exchangeable tags to perform multi-color imaging experiments.
| Cat. No. | Product Name | Activity | Emission Color | λex (nm) | λem (nm) | Application |
|---|---|---|---|---|---|---|
| 8102 | dTAG Janelia Fluor® 525 | Fluorogenic srTAG probe for live cell imaging of FBKP12F36V/L fusion proteins | Yellow | 530 | 560 | Confocal microscopy, SRM |
| 8103 | dTAG Janelia Fluor® 585 | Orange | 590 | 620 | ||
| 8101 | dTAG Janelia Fluor® 635 | Red | 640 | 665 |
Table 2: Summary of spectral data and imaging applications for dTAG Janelia Fluor® probes.
CoraFluor™ Haloalkanes
CoraFluor™ Haloalkanes are terbium-based time-resolved Förster resonance energy transfer (TR-FRET) donors for TR-FRET assays development, such as target engagement and ternary complex assays. They are designed with a chloroalkane ligand for reactivity with haloalkane dehalogenase labeled proteins. They are exceptionally bright, providing unmatched assay sensitivity and stability in biological media over other commercially available TR-FRET donors.
They are compatible with common acceptor dyes such as FAM or FITC, AF488, GFP, mCherry, TMR and Cyanine 5, SE, enabling seamless assay integration in high throughput screening applications.
CoraFluor™ 1, thiol reactive, CoraFluor™ 1, amine reactive and CoraFluor™ 2, amine reactive also available.
CoraFluor is a trademark of Bio-Techne Corp.
| Cat. No. | Product Name | Activity | λex (nm) | Laser line (nm) | Application |
|---|---|---|---|---|---|
| 8817 | CoraFluor™ 1, Haloalkane | Cell impermeable terbium cryptate FRET donor for TR-FRET assay development | 340 | 337 | TR-FRET |
| 8818 | CoraFluor™ 2, Haloalkane | Cell permeable terbium cryptate FRET donor for live cell TR-FRET assay development assay development | 356 | 365 and 405 | TR-FRET |
Table 3: Summary of spectral data and imaging applications for CoraFluor™, Haloalkane probes.
References
- Cook et al. (2023) HaloTag-based reporters for fluorescence imaging and biosensing. Chembiochem. 24 e202300022. PMID: 36815462
- Du et al. (2024) Self-renewable tag for photostable fluorescence imaging of proteins. J.Am.Chem.Soc. 145 18968. PMID: 37596976
- Grimm et al. (2017) A general method to fine-tune fluorophores for live-cell and in vivo imaging. Nat. Methods 17 987. PMID: 28869757
- Payne et al (2021) Bright and stable luminescent probes for target engagement profiling in live cells. Nat.Chem.Biol. 17 1168. PMID: 34675420
- Tsai et al (2017) Nuclear microenvironments modulate transcription from low-affinity enhancers. Elife 6 e28975. PMID: 29095143
Literature for Self-labeling Tags
Tocris offers the following scientific literature for Self-labeling Tags to showcase our products. We invite you to request* your copy today!
*Please note that Tocris will only send literature to established scientific business / institute addresses.
Fluorescent Dyes and Probes Research Product GuideUpdated
This product guide provides a background to the use of Fluorescent Dyes and Probes, as well as a comprehensive list of our:
- Fluorescent Dyes, including Janelia Fluor® Dyes
- Fluorescent Probes for Advanced Microscopy and Live Cell Imaging
- Fluorescent Probes to Support In Vivo, Deep Tissue, and Bioluminescence Imaging
- Fluorescent Probes and Reagents for Organoids and 3D Cell Culture Imaging
- Aptamer-based RNA Imaging Reagents
- Fluorescent Probes for Imaging Bacteria
- TSA VividTM Fluorophore Kits
- TSA Reagents for Enhancing IHC, ICC & FISH Signals
- Tissue Clearing Kits and Reagents
Our guide highlights the use of Fluorescent Dyes and Probes in research and provides background information on various imaging techniques.
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