Shop All Labels & Labeling Kits

5-TAMRA, SE (5-Carboxytetramethylrhodamine, Succinimidyl Ester), single isomer (Invitrogen™)

The amine-reactive 5-TAMRA, SE and its conjugates yield bright, pH-insensitive orange-red fluorescence (approximate excitation/emission maxima ~546/579) with good photostability.

CellTrace™ BODIPY™ TR Methyl Ester (Lipophilic Counterstain For GFP) (Invitrogen™)

The red-fluorescent CellTrace™ BODIPY® TR methyl ester is an excellent counterstain for cells and tissues that are expressing GFP. CellTrace™ BODIPY® TR methyl ester readily permeates cell membranes and selectively stains mitochondria and endomembranous organelles such as endoplasmic reticulum and the Golgi apparatus, but does not appear to localize in the plasma membrane. CellTrace™ BODIPY® TR methyl ester staining is retained after paraformaldehyde fixation.

Qtracker™ 655 Cell Labeling Kit (Trial Size) (Invitrogen™)

The Qtracker® 655 Cell Labeling Kit uses a custom targeting peptide to deliver far red-fluorescent Qdot® 655 probe (ex/em 405–615/655 nm) into the cytoplasm of live cells. Once inside the cells, the Qdot® 655 probe provides an intense, stable fluorescence that can be traced through several generations and is not transferred to adjacent cells in a population. This trial-size version offers a convenient introduction to the Qtracker® cell labeling technology at an affordable price.

Need a different emission spectrum or longer tracking? View our other mammalian cell tracking products.

Features of the Qtracker® Cell Labeling kits include:

• Qtracker® probes allow for continuous illumination, without photobleaching or degradation problems often associated with organic dyes
• Simple to use—add Qtracker® labeling solution to cells in serum-containing media, incubate one hour, then detect and track the cells
• Provide an intense, stable fluorescence that can be traced through several generations
• Excellent tool for long-term tracking or imaging studies of live cells, including migration, motility, morphology, and other cell function assays

The Qtracker® Cell Labeling kits use a custom targeting peptide to deliver Qdot® probes into the cytoplasm of live cells. Since the cytoplasmic delivery mechanism is not mediated by a specific enzyme, no cell-type specificity has been observed. Maximum delivery is typically accomplished in less than 1 hour.

The Qdot® probes are compatible with serum-sensitive cells. The intense fluorescence from the Qdot® probes is maintained in complex cellular environments and under various biological conditions including changes in intracellular pH, temperature, and metabolic activity.

Long-Lasting, Targeted Signal
Use of Qtracker® Cell Labeling kits results in the ability to observe labeled cells with extensive continuous illumination, without photobleaching or degradation problems often associated with organic dyes. Once inside the cells, the Qdot® probes are localized to cytoplasmic vesicles and are inherited by daughter cells for at least six generations. Fluorescence from the Qdot® probes can be detected for up to a week after delivery in some cell lines. The long-term cellular retention of the Qdot® probes results in an ideal tool for studying cell motility, migration, differentiation, morphology, and many other cellular function studies. Since the Qtracker® labels do not leak out of intact labeled cells and are not transferred to adjacent cells, the Qtracker® Cell Labeling kits result in a targeted signal.

Monitor the Signal on Multiple Platforms
Qtracker® reagent-labeled live cells can be easily monitored on a variety of platforms, including flow cytometry, fluorescence/confocal microscopy, fluorescence microplate readers, and high-content imaging systems.

Minimal Impact on Live Cells
The cytotoxicity of the materials used in Qtracker® Cell Labeling kits has been tested in a variety of cell lines including CHO, HeLa, U-118, 3T3, HUVEC, and Jurkat cells. Labeling with Qtracker® Cell Labeling kits appears to exert minimal impact on cellular surface marker expression, cell proliferation, cellular enzyme activity, and cell motility.

Useful in a Variety of Cell Tracing Studies
Post-labeling, researchers have demonstrated a wide variety of applications for Qtracker®-labeled cells, including cell co-culture and cell assembly into heterotypic assemblies, multilineage differentiation, trans-differentiation versus cell fusion, embryonic and mesenchymal stem cell tracking, and cell migration dynamics.

Alexa Fluor™ 647 Azide, Triethylammonium Salt (Invitrogen™)

The far red-fluorescent Alexa Fluor® 647 azide is reactive with terminal alkynes via a copper-catalyzed click reaction. The bright and photostable fluorophore can be for used with flow cytometry, microscopy and HCS

Biotin Alkyne (PEG4 carboxamide-Propargyl Biotin) (Invitrogen™)

The hapten, biotin azide is reactive with terminal via a copper-catalyzed click reaction. Biotin can be subsequently detected with streptavidin, avidin or NeutrAvidin® biotin-binding protein.

Dansyl Ethylenediamine, 5-Dimethylaminonaphthalene-1-(N-(2-Aminoethyl))sulfonamide (Invitrogen™)

The primary aliphatic amine of dansyl ethylenediamine 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). This fluorophore is lipophilic and environmentally-sensitive.

Tetramethylrhodamine-6-Isothiocyanate (6-TRITC; R isomer) (Invitrogen™)

The amine-reactive tetramethylrhodamine-6-isothiocyanate (6-TRITC; R isomer) can be used to can be used to create bright red-orange fluorescent bioconjugates with excitation/emission maxima ~555/580 nm.

Zenon™ Alexa Fluor™ 546 Rabbit IgG Labeling Kit (Invitrogen™)

Zenon® labeling technology provides a fast, versatile, and reliable method for adding a fluorescent label to an antibody. You need only a small amount of starting material, and the method is optimized for efficient labeling of antibodies in serum, ascites fluid, or hybridoma suspensions. Antibody conjugates formed using Zenon® technology may be used in any protocol where a directly labeled primary antibody is suitable, including flow cytometry, imaging, and high-throughput applications. This exclusive Molecular Probes® Zenon® labeling technology greatly simplifies the use of multiple mouse-derived antibodies in the same staining protocol.

Important Features of Zenon® Labeling Technology:

• Labeled antibodies typically ready to use in 10 minutes
• Requires only 1–20 μg primary antibody
• Simple, no purification required
• Flexible–over 24 fluorophores plus biotin, HRP, alkaline phosphatase, and TSA to choose from
• Multiplex with other mouse monoclonal antibodies simultaneously


Save Time and Antibody
Each kit comes with affinity-purified monovalent Fab fragment of a goat anti-Fc antibody (or, in the case of the Zenon® Goat IgG Labeling Kits, a rabbit anti-Fc antibody) that has been conjugated to one of our premier Alexa Fluor® dyes or to Pacific Blue™, Pacific Orange™, fluorescein, or Texas Red®-X dyes, biotin R-phycoerythrin (R-PE), allophycocyanin (APC), HRP, or alkaline phosphatase.

Formation of the Fab–antibody complex with the Zenon® Antibody Labeling Kits is extremely fast (5 min for complex, 5 min for blocking step). And Zenon® labeling is a reliable and reproducible method, even with as low 0.4 μg in 2 μL of primary antibody. There is minimal waste of expensive or difficult-to-obtain antibodies when using the Zenon® Antibody Labeling Kits.

Preserve Primary Antibody Function and Affinities
Reactive dye labeling of primary antibodies can have unpredictable and undesirable outcomes. Among these are reduced binding affinities by label addition in the binding pocket. Zenon® antibody labeling approach, targeted to the Fc tail, avoids this concern.

Moreover the Zenon® dye- and enzyme-labeled Fab fragments have been affinity purified during their preparation to help ensure their high affinity and selectivity for the Fc portion of the corresponding primary antibody. The procedure for chemical labeling of the Fab fragments protects the Fc-binding site, resulting in more active labeling reagents.

Many Fluorophore and Enzyme Labels Available
Zenon® immunolabeling technology makes it very easy to change fluorescent color combinations or detection methodologies by simply using a different dye- or enzyme-labeled Fab fragment from our extensive selection of over 100 Zenon® Antibody Labeling Kits. If larger quantities or covalent attachment of the label is desired, see Antibody Labeling from A to Z or use our Labeling Chemistry Selection Tool for other choices.

Zenon® Technology Simplifies the Use of Multiple Antibodies of the Same Isotype in the Same Protocol
The stability of the Zenon® complex is sufficient to allow sequential (or simultaneous) labeling of different targets in cells and tissues with multiple antibody complexes. Subsequent to staining, an aldehyde-based fixation step can permanently block the transfer of Zenon® labels between different primary antibodies and will preserve the staining pattern.

We’ll Make a Custom Antibody Conjugate for You
If you can’t find what you’re looking for in our stocked list, we’ll prepare a custom antibody 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.

For Research Use Only. Not intended for animal or human therapeutic or diagnostic use.

Related Links:

Zenon® Labeling Technology
Zenon® Technology: Versatile Reagents for Immunolabeling—Section 7.3

Zenon™ Alexa Fluor™ 647 Mouse IgG1 Labeling Kit (Invitrogen™)

Zenon® labeling technology provides a fast, versatile, and reliable method for adding a fluorescent label to an antibody. You need only a small amount of starting material, and the method is optimized for efficient labeling of antibodies in serum, ascites fluid, or hybridoma suspensions. Antibody conjugates formed using Zenon® technology may be used in any protocol where a directly labeled primary antibody is suitable, including flow cytometry, imaging, and high-throughput applications. This exclusive Molecular Probes® Zenon® labeling technology greatly simplifies the use of multiple mouse-derived antibodies in the same staining protocol.

Important Features of Zenon® Labeling Technology:

• Labeled antibodies typically ready to use in 10 minutes
• Requires only 1–20 μg primary antibody
• Simple, no purification required
• Flexible–over 24 fluorophores plus biotin, HRP, alkaline phosphatase, and TSA to choose from
• Multiplex with other mouse monoclonal antibodies simultaneously


Save Time and Antibody
Each kit comes with affinity-purified monovalent Fab fragment of a goat anti-Fc antibody (or, in the case of the Zenon® Goat IgG Labeling Kits, a rabbit anti-Fc antibody) that has been conjugated to one of our premier Alexa Fluor® dyes or to Pacific Blue™, Pacific Orange™, fluorescein, or Texas Red®-X dyes, biotin R-phycoerythrin (R-PE), allophycocyanin (APC), HRP, or alkaline phosphatase.

Formation of the Fab–antibody complex with the Zenon® Antibody Labeling Kits is extremely fast (5 min for complex, 5 min for blocking step). And Zenon® labeling is a reliable and reproducible method, even with as low 0.4 μg in 2 μL of primary antibody. There is minimal waste of expensive or difficult-to-obtain antibodies when using the Zenon® Antibody Labeling Kits.

Preserve Primary Antibody Function and Affinities
Reactive dye labeling of primary antibodies can have unpredictable and undesirable outcomes. Among these are reduced binding affinities by label addition in the binding pocket. Zenon® antibody labeling approach, targeted to the Fc tail, avoids this concern.

Moreover the Zenon® dye- and enzyme-labeled Fab fragments have been affinity purified during their preparation to help ensure their high affinity and selectivity for the Fc portion of the corresponding primary antibody. The procedure for chemical labeling of the Fab fragments protects the Fc-binding site, resulting in more active labeling reagents.

Many Fluorophore and Enzyme Labels Available
Zenon® immunolabeling technology makes it very easy to change fluorescent color combinations or detection methodologies by simply using a different dye- or enzyme-labeled Fab fragment from our extensive selection of over 100 Zenon® Antibody Labeling Kits. If larger quantities or covalent attachment of the label is desired, see Antibody Labeling from A to Z or use our Labeling Chemistry Selection Tool for other choices.

Zenon® Technology Simplifies the Use of Multiple Antibodies of the Same Isotype in the Same Protocol
The stability of the Zenon® complex is sufficient to allow sequential (or simultaneous) labeling of different targets in cells and tissues with multiple antibody complexes. Subsequent to staining, an aldehyde-based fixation step can permanently block the transfer of Zenon® labels between different primary antibodies and will preserve the staining pattern.

We’ll Make a Custom Antibody Conjugate for You
If you can’t find what you’re looking for in our stocked list, we’ll prepare a custom antibody 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.

For Research Use Only. Not intended for animal or human therapeutic or diagnostic use.

Related Links:

Zenon® Labeling Technology
Zenon® Technology: Versatile Reagents for Immunolabeling—Section 7.3

DyLight™ 594 Microscale Antibody Labeling Kit (Thermo Scientific™)

Thermo Scientific DyLight 594 Amine-Reactive Dye is an NHS ester-activated derivative of high-performance DyLight 594 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.

DyLight 594 provides vibrant red fluorescence with better performance than Alexa Fluor™ 594 and Texas Red™ dye for fluorescent 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 594 Amine-Reactive Dye is available as a stand-alone reagent or as part of two antibody labeling kit sizes.

Features of DyLight 594 NHS Ester:

High performance—DyLight 594 shows brighter fluorescence than Alexa Fluor 594 and Texas Red
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 594 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 DyLight 594 Amine-Reactive 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 594 Amine-Reactive Dye to be provided in multiple formats with flexible protocols to achieve efficient degrees of labeling.

Related Products
DyLight™ 594 NHS Ester
DyLight™ 594 Antibody Labeling Kit

EZ-Link™ Biocytin (Thermo Scientific™)

Thermo Scientific EZ-Link Biocytin is a simple variant of biotin that contains a primary amine in its valeric acid chain, which provides the essential backbone for construction of certain long-chain and trifunctional biotinylation reagents.

Features of EZ-Link Biocytin:

Biotinylation—label molecules and surfaces for assays or affinity purification methods involving avidin or streptavidin probes and resins
Amine-activated—primary amine can be crosslinked to proteins and material surfaces using EDC and other crosslinkers
Lysine derivative—functions as a biotin-tagged amino acid; potentially useful as a control or quenching reagent in biotin assay methods
Medium length—spacer arm (total length added to target) is 20.1 angstroms, representing a 7-atom extension of the native biotin valeric acid

Biocytin is ε-N-[d-biotinyl]-L-lysine, a compound formed by conjugation of the epsilon amine of lysine to the valeric acid side chain of biotin. It contains terminal carboxyl and amino groups, which provide functional handles for derivatization or conjugation to proteins, surfaces and other molecules. Carbodiimide (EDC) and NHS-ester crosslinker chemistries are most often utilized for covalent modifications involving biocytin. The compound is also useful as an amino acid control or biotin standard in assay methods involving streptavidin binding.

We manufacture biotin reagents to ensure the highest possible overall product integrity, consistency and performance for the intended research applications.

Amino-biotin compounds can be conjugated to functional groups of proteins and other molecules in a variety of ways. The most common method is to crosslink the terminal primary amine to carboxyl groups using . Carboxyl groups (-COOH) occur in aspartate or glutamate residues and the carboxy-terminus of polypeptides. When activated with EDC (Part No. 22980), carboxylates react with amino (—NH2) groups to form amide bonds.

Biocytin has both carboxyl and amino groups. Therefore, to prevent self-conjugation of biocytin, EDC-mediated reaction schemes with this compound are usually done in two steps, aided by Sulfo-NHS (Part No. 24510): (1) Activate a carboxylate molecule using EDC and Sulfo-NHS, followed by complete removal or inactivation of the EDC reagent; then (2) Add Biocytin to allow its primary amine to react with the Sulfo-NHS ester-activated carboxyl groups. See NHS-ester Chemistry. Subsequently, the remaining carboxyl group of biocytin could be conjugated to yet another molecule. For example, biocytin is the starting material for synthesis of Sulfo-SBED (Part No. 33033), a trifunctional reagent.

DyLight™ 650-4xPEG Maleimide (Thermo Scientific™)

Thermo Scientific DyLight 650-4xPEG Sulfhydryl-Reactive Dye is a maleimide-activated derivative of our high-performance DyLight 650 Dye used to fluorescently label cysteine-containing peptides, proteins, or other biomolecular probes.

The DyLight 650-4xPEG Dye contains 4 polyethylene glycol (PEG) chains that are non-toxic, enhance fluorescence, and reduce nonspecific binding of conjugates made with them. Conjugates made with DyLight 650-4xPEG Dye can be used as molecular probes for cellular and in vivo imaging, flow cytometry, IHC, and other fluorescence detection methods. The PEG chains also improve solubility of the dyes and labeled molecules in aqueous solution, aid in cell permeability, and improve tissue retention.

Features of DyLight 650-4xPEG Maleimide:

High fluorescence intensity—significantly brighter fluorescence than Alexa Fluor™ 647
PEGylated—improves solubility in aqueous solution and aids in cell permeability
Specific—maleimide-activated dye labels proteins and other molecules at reduced sulfhydryls (-SH)

Applications:
• Fluorescence microscopy
In vivo or ex vivo imaging
• Cell-based assays
• Flow cytometry/fluorescence-activated cell sorting (FACS)

DyLight 650-4xPEG Sulfhydryl-Reactive Dye is activated with a maleic acid imide (maleimide) moiety to form a reactive alkylation reagent. Labeling occurs through reaction of the maleimide-activated dye with reduced sulfhydryl groups (-SH) to form stable thioether bonds. Maleimides are specific for sulfhydryl groups between pH 6.5–7.5. Learn more about maleimide chemistry.

Click-iT™ Biotin sDIBO Alkyne (Invitrogen™)

Click-iT Biotin sDIBO Alkyne reacts with azides via a copper-free Click chemistry reaction to produce biotin bioconjugates. sDIBO alkynes are improved versions of our original DIBO cyclooctynes, yielding conjugates that are less “sticky” and give lower signal background in biological samples. Copper-free Click bio-conjugation reactions are ideal for surface labeling of live cells and also minimize damage to enzymes and fluorescent proteins like GFP or R-PE. Macromolecules that have been azide-modified enzymatically, chemically, or metabolically can be now be labeled easily, yielding more soluble bioconjugates with improved biological labeling utility.

• More soluble than DIBO cyclooctynes leading to more soluble conjugates
• Minimal background potential in cells and tissues compared to original DIBO cycloctynes

Learn more about avidin-biotin detection ›

Click-IT™ Tetramethylrhodamine (TAMRA) Protein Analysis Detection Kit (Invitrogen™)

The Click-iT® Tetramethylrhodamine (TAMRA) Glycoprotein Detection Kit provides the second part of the simple and robust two-step technique to identify and characterize glycoproteins by one- or two-dimensional gel electrophoresis. In step two, after the incorporation of the azide handle into protein glycan structures with either a Click-iT® metabolic labeling reagent or the Click-iT® Enzymatic Labeling system, the azide-modified glycoproteins are detected via the chemoselective ligation or click reaction between an azide and an alkyne. Gels with TAMRA labeled glycoproteins can be subsequently stained with the Multiplexed Proteomics™ technologies, SYPRO® Ruby total protein stain and PRO-Q® Emerald glycoprotein stain for the differential analysis of glycoprotein subclasses, total proteins and total glycoproteins in the same gel. Click-iT® modified glycoproteins are also compatible with downstream LC-MS/MS and MALDI MS analysis for identification.

EZ-Link™ Iodoacetyl-PEG2-Biotin (Thermo Scientific™)

Thermo Scientific EZ-Link Iodoacetyl-PEG2-Biotin is a mid-length, haloacetyl-activated, sulfhydryl-reactive biotinylation reagent that contains a 2-unit ethylene glycol in its spacer arm for increased water-solubility characteristics.

Features of EZ-Link Iodoacetyl-PEG2-Biotin:

Protein labeling—biotinylate antibodies or other proteins for use in protein methods
Thiol-reactive—reacts with sulfhydryls (-SH), such as the side-chain of cysteine (C)
Iodoacetyl-activated—perform reactions in the dark at pH 7.5 to 8.5 in Tris or borate buffer
Pegylated—spacer arm contains a hydrophilic, 2-unit, polyethylene glycol (PEG) group
Enhances solubility—pegylation imparts water solubility to the biotinylated molecule, helping to prevent aggregation of biotinylated antibodies stored in solution
Irreversible—forms permanent thioether bonds; spacer arm cannot be cleaved
Solubility—can be dissolved directly in aqueous buffers for labeling reactions
Medium length—spacer arm (total length added to target) is 24.7 angstroms

Iodoacetyl-PEG2-Biotin enables simple and efficient biotin labeling of antibodies, cysteine-containing peptides and other thiol-containing molecules. The iodoacetyl group reacts with reduced thiols (sulfhydryl groups,—SH) at alkaline pH to form stable thioether bond. The hydrophilic, 2-unit polyethylene glycol (PEG) spacer arm imparts water solubility that is transferred to the biotinylated molecule, thus reducing aggregation of labeled proteins stored in solution. The PEG segment adds length and flexibility to the spacer arm, minimizing steric hindrance involved with binding to avidin molecules.

We manufacture biotin reagents to ensure the highest possible overall product integrity, consistency and performance for the intended research applications.

Biotinylation reagents differ in reactivity, length, solubility, cell permeability and cleavability. Three types of sulfhydryl-reactive compounds are available: maleimido, iodoacetyl and pyridyldithiol. Iodoacetyl reagents specifically react with sulfhydryl groups (-SH) at pH 8.3 to form permanent thioether bonds.

In proteins, sulfhydryls exist where there are cysteine (C) residues. Cystine disulfide bonds must be reduced to make sulfhydryl groups available for labeling. Hinge-region disulfide bridges of antibodies can be selectively reduced to make functional half-antibodies that can be labeled.