Shop All Labels & Labeling Kits

5-TAMRA (5-Carboxytetramethylrhodamine), single isomer (Invitrogen™)

Tetramethylrhodamine (TMR, TRITC) has been a widely used fluorophore for preparing bioconjugates, especially fluorescent antibody and avidin derivatives used in immunochemistry. Under the name TAMRA, the carboxylic acid of 5-TAMRA has also achieved prominence as a dye for oligonucleotide labeling and automated DNA sequencing applications.

6-TAMRA (6-Carboxytetramethylrhodamine), single isomer (Invitrogen™)

Tetramethylrhodamine (TMR, TRITC) has been a widely used fluorophore for preparing bioconjugates, especially fluorescent antibody and avidin derivatives used in immunochemistry. Under the name TAMRA, the carboxylic acid of 6-TAMRA has also achieved prominence as a dye for oligonucleotide labeling and automated DNA sequencing applications.

DyLight™ 775-B2 NHS Ester (Thermo Scientific™)

Thermo Scientific DyLight near-infrared specialty dyes, comparable to Alexa Fluor and IRDye NIR dyes, can be used to label antibodies, peptides, and other proteins at primary amines. DyLight 775-B2 dye has a structure based on the benzopyrillium core, with 2 sulfonates. It has excitation and emission peaks at 772 and 787 nm, respectively (in ethanol).

General characteristics of DyLight near-infrared emitting specialty dyes:

Large selection—the largest family of dyes available for NIR fluorescence applications
NHS ester reactive group—allows immediate labeling of antibodies, proteins, peptides and other amine-containing molecules through amide bond formation
Broad spectrum of water solubilities—choose from hydrophilic to hydrophobic dyes to optimize the right dye label for the best performance in a given application
NIR dyes avoid background interference—DyLight NIR Dyes avoid fluorescence interference or quenching effects from biomolecules present in samples
Excellent signal penetration through cells and tissues—DyLight NIR Dyes provide the optimal window for excitation and emission for in vivo imaging applications

DyLight NIR Dyes are a family of labeling agents that can be used for bright fluorescence detection in cell-based imaging or in vivo imaging applications. NIR dyes can be selected based upon their characteristic excitation and emission properties or relative hydrophilicity and hydrophobicity attributes. Dyes that contain a greater number of negatively charged sulfonates generally will have greater water solubility than dyes with fewer sulfonates. More hydrophobic dyes often provide better cell penetrating ability in vivo, while more hydrophilic dyes have less nonspecific binding potential. Each dye contains an amine-reactive NHS ester for simple modification of antibodies, proteins, peptides or other biomolecules through amide bond formation. NIR dyes are best for imaging through tissues and away from indigenous fluorescent biomolecule interference or quenching. DyLight Near Infrared Dyes represent the largest selection of fluorescent labels that are commercially available.

Criteria to consider when choosing a DyLight NIR Specialty Dye
• Excitation and emission wavelengths—choose the best dye to match the excitation and emission capabilities of your instrument
• Water solubility—choose a DyLight NIR Dye based on its relative hydrophilicity, which directly correlates to the number of negatively-charged sulfonates it has on its core structure. More hydrophilic dyes are best at maintaining water solubility of a labeled antibody and limiting the nonspecific binding of the conjugate. More hydrophobic dyes often are best at penetrating tissues and cell membranes in vivo, meaning that dyes with fewer sulfonates may work best for some applications.
• DyLight Dye selection—the broad selection of NIR dyes allows a number of candidate dyes to be tested in a given application for optimal performance.

Applications:
In vivo or ex vivo imaging
• Tumor imaging with labeled peptides
• NIR fluorescence (NIRF) imaging of labeled silica nanoparticles
• NIR in vitro imaging and characterization
• Determination of thermal stability
• Cytotoxicity assays
• Molecular imaging
• UV-VIS-NIR spectroscopy
• Fluorescence correlation spectroscopy
• MRI applications
• DNA sequencing
• Primer labeling for PCR
• 2-D gel electrophoresis
• Flow cytometry/fluorescence-activated cell sorting (FACS)
• Laser scanning confocal microscopy

Related Products
DyLight™ 775-B3 NHS Ester
DyLight™ 775-B4 NHS Ester

BODIPY™ FL EDA, 4,4-Difluoro-5,7-Dimethyl-4-Bora-3a,4a-Diaza-s-Indacene-3-Propionyl Ethylenediamine, Hydrochloride (Invitrogen™)

BODIPY® FL EDA can be reversibly coupled to aldehydes and ketones to form a Schiff base - which can be reduced to a generate stable amine derivative by sodium borohydride (NaBH4) or sodium cyanoborohydride (NaCNH3). Carboxylic acids of proteins and other water-soluble biopolymers can be coupled to this molecule in aqueous solution using water-soluble carbodiimides such as EDAC (E2247).

6-TAMRA, SE (6-Carboxytetramethylrhodamine, Succinimidyl Ester), single isomer (Invitrogen™)

The isomeric 6-TAMRA, SE is an amine-reactive form of tetramethylrhodamine. The single-isomer preparations of TAMRA are most important for high-resolution techniques such as DNA sequencing and capillary electrophoresis. 6-TAMRA is one of the traditional fluorophores used for automated DNA sequencing.

DyLight™ 775-B3 NHS Ester (Thermo Scientific™)

Thermo Scientific DyLight near-infrared specialty dyes, comparable to Alexa Fluor and IRDye NIR dyes, can be used to label antibodies, peptides, and other proteins at primary amines. DyLight 775-B3 dye has a structure based on the benzopyrillium core, with 3 sulfonates. It has excitation and emission peaks at 770 and 788 nm, respectively (in ethanol).

General characteristics of DyLight near-infrared emitting specialty dyes:

Large selection—the largest family of dyes available for NIR fluorescence applications
NHS ester reactive group—allows immediate labeling of antibodies, proteins, peptides and other amine-containing molecules through amide bond formation
Broad spectrum of water solubilities—choose from hydrophilic to hydrophobic dyes to optimize the right dye label for the best performance in a given application
NIR dyes avoid background interference—DyLight NIR Dyes avoid fluorescence interference or quenching effects from biomolecules present in samples
Excellent signal penetration through cells and tissues—DyLight NIR Dyes provide the optimal window for excitation and emission for in vivo imaging applications

DyLight NIR Dyes are a family of labeling agents that can be used for bright fluorescence detection in cell-based imaging or in vivo imaging applications. NIR dyes can be selected based upon their characteristic excitation and emission properties or relative hydrophilicity and hydrophobicity attributes. Dyes that contain a greater number of negatively charged sulfonates generally will have greater water solubility than dyes with fewer sulfonates. More hydrophobic dyes often provide better cell penetrating ability in vivo, while more hydrophilic dyes have less nonspecific binding potential. Each dye contains an amine-reactive NHS ester for simple modification of antibodies, proteins, peptides or other biomolecules through amide bond formation. NIR dyes are best for imaging through tissues and away from indigenous fluorescent biomolecule interference or quenching. DyLight Near Infrared Dyes represent the largest selection of fluorescent labels that are commercially available.

Criteria to consider when choosing a DyLight NIR Specialty Dye
• Excitation and emission wavelengths—choose the best dye to match the excitation and emission capabilities of your instrument
• Water solubility—choose a DyLight NIR Dye based on its relative hydrophilicity, which directly correlates to the number of negatively-charged sulfonates it has on its core structure. More hydrophilic dyes are best at maintaining water solubility of a labeled antibody and limiting the nonspecific binding of the conjugate. More hydrophobic dyes often are best at penetrating tissues and cell membranes in vivo, meaning that dyes with fewer sulfonates may work best for some applications.
• DyLight Dye selection—the broad selection of NIR dyes allows a number of candidate dyes to be tested in a given application for optimal performance.

Applications:
In vivo or ex vivo imaging
• Tumor imaging with labeled peptides
• NIR fluorescence (NIRF) imaging of labeled silica nanoparticles
• NIR in vitro imaging and characterization
• Determination of thermal stability
• Cytotoxicity assays
• Molecular imaging
• UV-VIS-NIR spectroscopy
• Fluorescence correlation spectroscopy
• MRI applications
• DNA sequencing
• Primer labeling for PCR
• 2-D gel electrophoresis
• Flow cytometry/fluorescence-activated cell sorting (FACS)
• Laser scanning confocal microscopy

Related Products
DyLight™ 775-B2 NHS Ester
DyLight™ 775-B4 NHS Ester

5-ROX (5-Carboxy-X-Rhodamine, Triethylammonium Salt), single isomer (Invitrogen™)

The carboxylic acid of 5-ROX is used for oligonucleotide labeling and automated DNA sequencing applications. Conjugates of this dye have longer-wavelength spectra than the spectra of Lisaamine™ rhodamine B conjugates, but somewhat shorter-wavelength spectra than those of Texas Red® conjugates.

DyLight™ 680 Antibody Labeling Kit (Thermo Scientific™)

The Thermo Scientific DyLight 680 Antibody Labeling Kit contains an NHS ester-activated derivative of high-performance DyLight 680 used to fluorescently label antibodies and other proteins that are then used as molecular probes for cellular imaging and other fluorescence detection methods. The standard size kit contains all necessary components to perform three separate labeling reactions using 1 mg of IgG or similar quantities of other proteins—the amine-reactive DyLight 680 NHS-ester in convenient single-use vials, as well as purification resin and spin columns for the preparation of ready-to-use conjugate..

DyLight 680 produces near-infrared (IR) fluorescence that replaces other near-IR dyes, including Cy5.5™ dye and Alexa Fluor™ 680, and is ideal for multi-color applications.The high water solubility of DyLight Fluors means that a high dye-to-protein ratio can be attained without causing precipitation of the conjugates. DyLight 680 Amine-Reactive Dye is also available as a stand-alone reagent.

Features of DyLight 680 NHS-Ester:

High performance—DyLight 680 fluoresces brighter than Alexa Fluor 680 and Cy5.5 dye
Specific—NHS ester-activated dye labels proteins and other molecules at primary amines (-NH2)
Convenient kit sizes—standard and microscale sizes are offered to match your experimental needs
Optimized procedure—following the standard protocol results in antibodies with excellent dye:protein ratios and recovery rates for optimum activity and fluorescence labeling

Applications:
• Primary antibody labeling for immunofluorescence microscopy, immunohistochemistry (IHC), Western blotting or ELISA assay
• Target protein labeling for in vitro and in vivo fluorescent detection strategies

DyLight 680 Amine-Reactive Dye is activated with an N-hydroxysuccinimide (NHS) ester moiety to react with exposed N-terminal α-amino groups or the ε-amino groups of lysine residues to form stable amide bonds. Learn more about NHS ester chemistry.

Typical labeling reactions require the dye to first be dissolved in anhydrous dimethyl formamide (DMF) or another suitable organic solvent before adding a specific molar amount of dye to an amine-free buffer containing the protein to be labeled. However, the high solubility of DyLight Fluors permits protein solutions to be added directly to specific amounts of the labeling reagent. This feature allows DyLight 680 Amine-Reactive Dye to be provided in multiple formats with flexible protocols to achieve efficient degrees of labeling.

Related Products
DyLight™ 680 NHS-Ester
DyLight™ 680 Microscale Antibody Labeling Kit

DyLight™ 550-Phosphine (Thermo Scientific™)

Thermo Scientific DyLight Fluor Phosphine Reagents are phosphine-activated fluorescent dyes for specific labeling and detection of azide-tagged molecules, which enables use of fluorescence imaging in metabolic labeling strategies.

When used in combination with azide labeling strategies, phosphine-activated DyLight Fluors enable selective fluorescent labeling for detection of protein interactions and post-translational modifications using fluorescence imaging technologies. The phosphine group conjugates to azide groups by the Staudinger reaction mechanism. Azide groups can be introduced into proteins or other cellular targets through in vivo labeling with azide-tagged derivatives of naturally occurring metabolic building blocks. Because neither phosphines nor azides are present in biological systems, they comprise a chemoselective (mutually specific) ligation pair for labeling and conjugation.

General features of the phosphine-activated DyLight Fluors:

Soluble—easily dissolves in water-miscible solvents (e.g., DMSO) for subsequent dilution in aqueous reaction mixtures with cell lysates and other biological samples
Compatible—reaction chemistry occurs effectively in simple buffer conditions; requires no accessory reagents such as copper or reducing agents, and does not interfere with fluorescence applications
Chemoselective—the phosphine reactive group is specific in biological samples for bioorthogonal azide-tagged molecules, ensuring that fluorescent labeling is specific
High-performance fluorescence—DyLight 488, 550 and 650 are intense, highly stable fluorophores for green, orange and red fluorescent detection. (see DyLight Fluors)

Related Products
DyLight™ 488-Phosphine
DyLight™ 650-Phosphine

5-ROX, SE (5-Carboxy-X-Rhodamine, Succinimidyl Ester), single isomer (Invitrogen™)

The isomeric 5-ROX, SE is an amine-reactive form of carboxy-X-rhodamine and is widely used for oligonucleotide labeling and automated DNA sequencing applications.

DyLight™ 680 Microscale Antibody Labeling Kit (Thermo Scientific™)

The Thermo Scientific DyLight 680 Microscale Antibody Labeling Kit contains an NHS ester-activated derivative of high-performance DyLight 680 used to fluorescently label antibodies and other proteins that are then used as molecular probes for cellular imaging and other fluorescence detection methods. The microscale kit contains all of the necessary components to perform five separate labeling reactions using 100 µg of IgG—the amine-reactive DyLight 680 NHS-ester in convenient single-use vials, as well as purification resin and spin columns for the preparation of ready-to-use conjugate..

DyLight 680 produces near-infrared (IR) fluorescence that replaces other near-IR dyes, including Cy5.5™ dye and Alexa Fluor™ 680, and is ideal for multi-color applications.The high water solubility of DyLight Fluors means that a high dye-to-protein ratio can be attained without causing precipitation of the conjugates. DyLight 680 Amine-Reactive Dye is also available as a stand-alone reagent.

Features of DyLight 680 NHS-Ester:

High performance—DyLight 680 fluoresces brighter than Alexa Fluor 680 and Cy5.5 dye
Specific—NHS ester-activated dye labels proteins and other molecules at primary amines (-NH2)
Convenient kit sizes—standard and microscale sizes are offered to match your experimental needs
Optimized procedure—following the standard protocol results in antibodies with excellent dye:protein ratios and recovery rates for optimum activity and fluorescence labeling

Applications:
• Primary antibody labeling for immunofluorescence microscopy, immunohistochemistry (IHC), Western blotting or ELISA assay
• Target protein labeling for in vitro and in vivo fluorescent detection strategies

DyLight 680 Amine-Reactive Dye is activated with an N-hydroxysuccinimide (NHS) ester moiety to react with exposed N-terminal α-amino groups or the ε-amino groups of lysine residues to form stable amide bonds. Learn more about NHS ester chemistry.

Typical labeling reactions require the dye to first be dissolved in anhydrous dimethyl formamide (DMF) or another suitable organic solvent before adding a specific molar amount of dye to an amine-free buffer containing the protein to be labeled. However, the high solubility of DyLight Fluors permits protein solutions to be added directly to specific amounts of the labeling reagent. This feature allows DyLight 680 Amine-Reactive Dye to be provided in multiple formats with flexible protocols to achieve efficient degrees of labeling.

Related Products
DyLight™ 680 NHS-Ester
DyLight™ 680 Antibody Labeling Kit

DyLight™ 530-R2 NHS Ester (Thermo Scientific™)

Label peptides, antibodies and other proteins at primary amines with the rhodamine-based, water-soluble Thermo Scientific DyLight Green-emitting Specialty Dye, which is comparable to Alexa Fluor 532.

DyLight Green-emitting Dye is a labeling agent that provides bright fluorescence detection for imaging. Dyes that contain a greater number of negatively charged sulfonates generally will have greater water solubility than dyes with fewer sulfonates. More hydrophobic dyes often provide better cell penetration in vivo, while more hydrophilic dyes have less nonspecific binding potential. This dye contains 2 sulfonates for increased solubility and an amine-reactive NHS ester for simple modification of antibodies, proteins, peptides or other biomolecules through amide bond formation.

Features of DyLight 530-R2 NHS Ester:

NHS ester reactive group—allows immediate labeling of antibodies, proteins, peptides and other amine-containing molecules through amide bond formation
Water solubility—2 sulfonate groups increase the solubility of this dye over over less-sulfonated dyes

Applications:
• Imaging
• Antibody labeling
• Direct immunofluorescence staining
• Flow cytometry
• Fluorescence correlation spectroscopy
• ELISA
• Western blotting
• Protein microarrays
• Polymer labeling
• Peptide labeling
• Phalloidin labeling for actin staining

DyLight™ 650-Phosphine (Thermo Scientific™)

Thermo Scientific DyLight Fluor Phosphine Reagents are phosphine-activated fluorescent dyes for specific labeling and detection of azide-tagged molecules, which enables use of fluorescence imaging in metabolic labeling strategies.

When used in combination with azide labeling strategies, phosphine-activated DyLight Fluors enable selective fluorescent labeling for detection of protein interactions and post-translational modifications using fluorescence imaging technologies. The phosphine group conjugates to azide groups by the Staudinger reaction mechanism. Azide groups can be introduced into proteins or other cellular targets through in vivo labeling with azide-tagged derivatives of naturally occurring metabolic building blocks. Because neither phosphines nor azides are present in biological systems, they comprise a chemoselective (mutually specific) ligation pair for labeling and conjugation.

General features of the phosphine-activated DyLight Fluors:

Soluble—easily dissolves in water-miscible solvents (e.g., DMSO) for subsequent dilution in aqueous reaction mixtures with cell lysates and other biological samples
Compatible—reaction chemistry occurs effectively in simple buffer conditions; requires no accessory reagents such as copper or reducing agents, and does not interfere with fluorescence applications
Chemoselective—the phosphine reactive group is specific in biological samples for bioorthogonal azide-tagged molecules, ensuring that fluorescent labeling is specific
High-performance fluorescence—DyLight 488, 550 and 650 are intense, highly stable fluorophores for green, orange and red fluorescent detection. (see DyLight Fluors)

Related Products
DyLight™ 488-Phosphine
DyLight™ 550-Phosphine

Alexa Fluor™ 790 NHS Ester (Succinimidyl Ester) (Invitrogen™)

Alexa Fluor® 790 is a bright and photostable near-IR dye that is spectrally similar to indocyanine green (ICG) and the IRDye® 800 dye. Used for stable signal generation in imaging and flow cytometry, Alexa Fluor® 790 dye is water soluble and pH-insensitive from pH 4 to pH 10. Fluorescence of this long-wavelength Alexa Fluor® dye is not visible to the human eye but is readily detected by most imaging systems. As the longest-wavelength Alexa Fluor® dye, the emission is well separated from commonly used far-red fluorophores such as Alexa Fluor® 647 dye or allophycocyanin (APC), facilitating multicolor analysis. This fluorophore is also expected to be useful for small animal in-vivo imaging (SAIVI) applications or for two-color western applications with the LI-COR® Odyssey® infrared imaging system. In addition to reactive dye formulations, we offer Alexa Fluor® 790 dye conjugated to a variety of antibodies, peptides, proteins, tracers, and amplification substrates optimized for cellular labeling and detection.The NHS ester (or succinimidyl ester) of Alexa Fluor® 790 is the most popular tool for conjugating this dye to a protein or antibody. NHS esters can be used to label to the primary amines (R-NH2) of proteins, amine-modified oligonucleotides, and other amine-containing molecules. The resulting Alexa Fluor® conjugate will exhibit brighter fluorescence and greater photostability than the conjugates of other spectrally similar fluorophores.

Detailed information about this AlexaFluor® NHS ester:

Fluorophore label: Alexa Fluor® 790 dye
Reactive group: NHS ester
Reactivity: Primary amines on proteins and ligands, amine-modified oligonucleotides
Ex/Em of the conjugate: 784/814 nm
Extinction coefficient: 260,000 cm-1M-1
Spectrally similar dyes: indocyanine green (ICG) and the IRDye® 800 dye
Molecular weight: ~1750

Typical Conjugation Reaction
You can conjugate amine-reactive reagents with virtually any protein or peptide (the provided protocol is optimized for IgG antibodies). You can scale the reaction for any amount of protein, but the concentration of the protein should be at least 2 mg/mL for optimal results. We recommend trying three different degrees of labeling, using three different molar ratios of the reactive reagent to protein.

The Alexa Fluor® NHS ester is typically dissolved in high-quality anhydrous dimethylformamide (DMF) or dimethylsulfoxide (DMSO) (D12345), and the reaction is carried out in 0.1–0.2 M sodium bicarbonate buffer, pH 8.3, at room temperature for 1 hour. Because the pKa of the terminal amine is lower than that of the lysine epsilon-amino group, you may achieve more selective labeling of the amine terminus using a buffer closer to neutral pH.

Conjugate Purification
Labeled antibodies are typically separated from free Alexa Fluor® dye using a gel filtration column, such as Sephadex™ G-25, BioGel® P-30, or equivalent. For much larger or smaller proteins, select a gel filtration media with an appropriate molecular weight cut-off or purify by dialysis. We offer several purification kits optimized for different quantities of antibody conjugate:
Antibody Conjugate Purification Kit for 0.5-1 mg (A33086)
Antibody Conjugate Purification Kit for 20-50 µg (A33087)
Antibody Conjugate Purification kit for 50-100 µg (A33088)

Learn More About Protein and Antibody Labeling
We offer a wide selection of Molecular Probes® antibody and protein labeling kits to fit your starting material and your experimental setup. See our Antibody Labeling kits or use our Labeling Chemistry Selection Tool for other choices. To learn more about our labeling kits, read Kits for Labeling Proteins and Nucleic Acids—Section 1.2 in The Molecular Probes® Handbook.

We’ll Make a Custom Conjugate for You
If you can’t find what you’re looking for in our online catalog, we’ll prepare a custom antibody or protein conjugate for you. Our custom conjugation service is efficient and confidential, and we stand by the quality of our work. We are ISO 9001:2000 certified.

pHrodo™ Red, succinimidyl ester (pHrodo™ Red, SE) (Invitrogen™)

New pH-sensitive pHrodo™ Red dye conjugates give faster and more accurate results than any other phagocytosis assay

pHrodo™ Red dye conjugates are non-fluorescent outside the cell, but fluoresce brightly red in phagosomes

Get faster staining and more accurate results - without the need for wash steps or quencher dye


• Specific detection of phagocytosis and endocytosis
• Reduced signal variability and improved timing in sensitive experiments
• Multiplex with green dyes such as GFP, Fluo-4, or calcein


The fluorescence of the novel pHrodo™ Red dye dramatically increases as pH decreases from neutral to the acidic, making it an ideal tool to study phagocytosis and its regulation by drugs and/or environmental factors. The lack of fluorescence outside the cell eliminates the need for wash steps and quencher dyes.

Use the ready-made pHrodo™ Red E.coli BioParticles® conjugates in imaging or flow applications, or pHrodo™ Red SE, the activated succinimidyl ester, for labeling microorganisms or proteins of your choice.