The attachment of fluorescent dyes to proteins and other biomolecules is a common strategy used to better understand protein structure and function. These fluorescent proteins can be used in a broad range of applications including immunochemistry, fluorescence in situ hybridization (FISH), cell tracing, receptor labeling and fluorescence spectroscopy to name a few. Thermo Fisher Scientific offers an assortment of solutions to prepare fluorescent protein and antibody bioconjugates including labeling kits, stand-alone dyes and custom labeling services.
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What type of protein do you want to label with a fluorescent dye?
Antibodies
Find a wide selection of primary and secondary IgG antibody compatible labeling kits. Whether you are looking for site specific labeling strategies or are new to antibody labeling techniques, we have classic fluorophores and a broad range of Alexa Fluor dyes, Qdot nanocrystals, and more in kit format.
Proteins
Non-IgG antibody proteins molecular weight (MW) range 12–150 kDa can be fluorescently labeled with our antibody/protein labeling kits or using stand-alone amine- or thiol-reactive fluorescent dyes. Additionally, we offer custom labeling services.
Protein Labeling Kits
Thermo Fisher Scientific Protein Labeling Kits provide an easy way to covalently label 1–10 mg protein MW range 20–150 kDa with a fluorescent dye (including Alexa Fluor dyes).
- Label 1 mg protein
- Three labeling reactions in each kit
- Removal of BSA and other stabilizers is required prior to labeling
- Not compatible with amine-containing buffers (e.g., Tris)
- Ready to use in 90 minutes
- ~15 minutes actual hands-on time
The Protein Labeling Kits utilize an amine-reactive fluorophore to covalently attach the label to a protein or IgG antibody. Once formed, the covalent bond between the label and the protein is extremely stable—you are using the same chemistry we use to prepare our own primary and secondary conjugates.
Simply add ~1 mg purified protein (20–150 kDa) (in ~500 μL and free of amine-containing buffers such as Tris) to one of the vials containing a pre-measured quantity of amine-reactive dye and a magnetic stir bar. Purification is quickly achieved using the pre-packed spin column supplied with the kit, resulting in >85% recovery of antibody conjugate. The entire labeling and purification procedure can be completed in as little as 90 minutes. Removal of free dye is essential for the determination of the degree of labeling (DOL). Everything needed to perform three conjugations is provided.
Protein Labeling Kits selection guide
| Label | Ex/Em | Cat. No. |
|---|---|---|
| Alexa Fluor 350 | 346/442 | A10170 |
| Alexa Fluor 488 | 495/519 | A10235 |
| Alexa Fluor 532 | 532/553 | A10236 |
| Alexa Fluor 546 | 556/573 | A10237 |
| Alexa Fluor 555 | 555/565 | A20174 |
| Alexa Fluor 568 | 578/603 | A10238 |
| Alexa Fluor 594 | 590/617 | A10239 |
| Alexa Fluor 633 | 621/639 | A20170 |
| Alexa Fluor 647 | 650/665 | A20173 |
| Alexa Fluor 660 | 663/690 | A20171 |
| Alexa Fluor 680 | 679/702 | A20172 |
| Fluorescein | 494/518 | F10240 |
| Oregon Green 488 | 496/524 | O10241 |
| Pacific Blue dye | 410/455 | P30012 |
| Pacific Orange dye | 400/551 | P30014 |
| Texas Red dye | 595/615 | T10244 |
| Biotin | NA | D20655 |
Ex/Em = Fluorescence excitation and emission maxima, in nm.
Find more information about Alexa Fluor dyes and other fluorophores in the Fluorophore Selection Guide
Microscale Protein Labeling Kits
Our Microscale Protein Labeling Kits conveniently label small amounts (20–100 μg) of purified protein with a bright, photostable Alexa Fluor dye or biotin-XX.
- Labeled proteins ready in as little as 2 hours, requiring approximately 30 minutes actual hands-on time
- Label proteins with molecular weights between 12 and 150 kDa and quantities ranging from 20–100 µg
The Microscale Protein Labeling Kits use an amine-reactive fluorophore or biotin to covalently attach the label to the protein or IgG antibody. Once formed, the covalent bond between the label and the protein is extremely stable; you are using the same chemistry we use to prepare our own primary and secondary conjugates.
Unlike our other antibody labeling kits, these kits have been optimized for labeling proteins between 12 and 150 kDa, and so have utility in labeling antibodies as well as other proteins in that size range.
Any stabilizing proteins (e.g., BSA), must be removed prior to the labeling reaction. Convenient spin columns purify the labeled protein (Figure 2) with yields between 60 and 90%, depending on the molecular weight of the starting material. The entire labeling and purification procedure can be completed in as little as 2 hours—everything needed to perform three conjugations is provided in the kits.
Figure 2. Spin filter. (A) An empty filter showing the separate parts. (B) Appearance of the resin bed after centrifugation in a fixed-angle rotor or swinging bucket rotor.
Microscale Protein Labeling Kit selection guide
| Label | Ex/Em | Cat. No. |
|---|---|---|
| Alexa Fluor 488 | 495/519 | A30006 |
| Alexa Fluor 555 | 555/565 | A30007 |
| Alexa Fluor 594 | 590/617 | A30008 |
| Alexa Fluor 647 | 650/665 | A30009 |
| Biotin-XX | NA | B30010 |
| Biotin-XX (includes additional biotin quantitation assay) | NA | B30756 |
Ex/Em = Fluorescence excitation and emission maxima, in nm.
Find more information about Alexa Fluor dyes and other fluorophores in the Fluorophore Selection Guide
Protein Labeling Kits
Thermo Fisher Scientific Protein Labeling Kits provide an easy way to covalently label 1–10 mg protein MW range 20–150 kDa with a fluorescent dye (including Alexa Fluor dyes).
- Label 1 mg protein
- Three labeling reactions in each kit
- Removal of BSA and other stabilizers is required prior to labeling
- Not compatible with amine-containing buffers (e.g., Tris)
- Ready to use in 90 minutes
- ~15 minutes actual hands-on time
The Protein Labeling Kits utilize an amine-reactive fluorophore to covalently attach the label to a protein or IgG antibody. Once formed, the covalent bond between the label and the protein is extremely stable—you are using the same chemistry we use to prepare our own primary and secondary conjugates.
Simply add ~1 mg purified protein (20–150 kDa) (in ~500 μL and free of amine-containing buffers such as Tris) to one of the vials containing a pre-measured quantity of amine-reactive dye and a magnetic stir bar. Purification is quickly achieved using the pre-packed spin column supplied with the kit, resulting in >85% recovery of antibody conjugate. The entire labeling and purification procedure can be completed in as little as 90 minutes. Removal of free dye is essential for the determination of the degree of labeling (DOL). Everything needed to perform three conjugations is provided.
Protein Labeling Kits selection guide
| Label | Ex/Em | Cat. No. |
|---|---|---|
| Alexa Fluor 350 | 346/442 | A10170 |
| Alexa Fluor 488 | 495/519 | A10235 |
| Alexa Fluor 532 | 532/553 | A10236 |
| Alexa Fluor 546 | 556/573 | A10237 |
| Alexa Fluor 555 | 555/565 | A20174 |
| Alexa Fluor 568 | 578/603 | A10238 |
| Alexa Fluor 594 | 590/617 | A10239 |
| Alexa Fluor 633 | 621/639 | A20170 |
| Alexa Fluor 647 | 650/665 | A20173 |
| Alexa Fluor 660 | 663/690 | A20171 |
| Alexa Fluor 680 | 679/702 | A20172 |
| Fluorescein | 494/518 | F10240 |
| Oregon Green 488 | 496/524 | O10241 |
| Pacific Blue dye | 410/455 | P30012 |
| Pacific Orange dye | 400/551 | P30014 |
| Texas Red dye | 595/615 | T10244 |
| Biotin | NA | D20655 |
Ex/Em = Fluorescence excitation and emission maxima, in nm.
Find more information about Alexa Fluor dyes and other fluorophores in the Fluorophore Selection Guide
Microscale Protein Labeling Kits
Our Microscale Protein Labeling Kits conveniently label small amounts (20–100 μg) of purified protein with a bright, photostable Alexa Fluor dye or biotin-XX.
- Labeled proteins ready in as little as 2 hours, requiring approximately 30 minutes actual hands-on time
- Label proteins with molecular weights between 12 and 150 kDa and quantities ranging from 20–100 µg
The Microscale Protein Labeling Kits use an amine-reactive fluorophore or biotin to covalently attach the label to the protein or IgG antibody. Once formed, the covalent bond between the label and the protein is extremely stable; you are using the same chemistry we use to prepare our own primary and secondary conjugates.
Unlike our other antibody labeling kits, these kits have been optimized for labeling proteins between 12 and 150 kDa, and so have utility in labeling antibodies as well as other proteins in that size range.
Any stabilizing proteins (e.g., BSA), must be removed prior to the labeling reaction. Convenient spin columns purify the labeled protein (Figure 2) with yields between 60 and 90%, depending on the molecular weight of the starting material. The entire labeling and purification procedure can be completed in as little as 2 hours—everything needed to perform three conjugations is provided in the kits.
Figure 2. Spin filter. (A) An empty filter showing the separate parts. (B) Appearance of the resin bed after centrifugation in a fixed-angle rotor or swinging bucket rotor.
Microscale Protein Labeling Kit selection guide
| Label | Ex/Em | Cat. No. |
|---|---|---|
| Alexa Fluor 488 | 495/519 | A30006 |
| Alexa Fluor 555 | 555/565 | A30007 |
| Alexa Fluor 594 | 590/617 | A30008 |
| Alexa Fluor 647 | 650/665 | A30009 |
| Biotin-XX | NA | B30010 |
| Biotin-XX (includes additional biotin quantitation assay) | NA | B30756 |
Ex/Em = Fluorescence excitation and emission maxima, in nm.
Find more information about Alexa Fluor dyes and other fluorophores in the Fluorophore Selection Guide
Protein labeling with reactive dyes
We offer a wide selection of fluorescent dyes that can be used to fluorescently label proteins, including:
- Amine-reactive dyes that include active esters, carboxylates, isothiocyanates, and sulfonyl halides which react with primary amines within the protein. For more information about this chemistry, see the Molecular Probes Handbook—Chapter 1- Fluorophores and their amine-reactive derivatives.
- Thiol-reactive dyes that include including iodoacetamides, maleimides, benzylic halides, and bromomethylketones which react with cysteines within the protein or peptide. For more information about this chemistry, see the Molecular Probes Handbook—Chapter 2-Thiol-reactive probes.
Protein labeling custom service
We also offer custom protein labeling services for both commercial and research use.
Looking for fluorescent dye removal from protein sample?
Zeba Dye and Biotin Removal Spin Columns
Zeba Dye and Biotin Removal columns enable fast and efficient removal of non-reacted fluorescent dyes, biotin, reducing agents, and crosslinkers from samples containing proteins of interest that are larger than 7 kDa.
Looking for proteins that are already labeled with fluorescent dyes? Check out these options.
Fluorescent Secondary Antibodies
Fluorescent-dye conjugated secondary antibodies provide a much needed tool for identifying proteins in many applications including fluorescence imaging, western blotting, immunohistochemistry and more.
Biotin Binding Protein Conjugates
Streptavidin-based amplification techniques are widely used in flow cytometry, fluorescence imaging, western blotting, and microplate-based detection for increased signal output and greater sensitivity.
Other Fluorescent Protein Conjugates
Thermo Fisher Scientific offers a broad selection of fluorescent protein conjugates for basic research applications.
Looking to label other types of molecules with fluorescent dyes?
Nucleic acid labeling
Peptide labeling—see our Technical Note in the Molecular Probes Handbook—Note 9.2 Labeling small peptides with amine-reactive dyes in organic solvents—Note 9.2
Resources
For Research Use Only. Not for use in diagnostic procedures.