Shop All Protein Labeling Kits

Click-IT™ GlcNAz Metabolic Glycoprotein Labeling Reagent (tetraacetylated N-Azidoacetylglucosamine) (Invitrogen™)

The Click-iT® GlcNAz metabolic glycoprotein labeling reagent provides the first part of a simple and robust two-step technique to identify and characterize intracellular O-GlcNAc glycoproteins. In step one, cultured cells are incubated with the azide-modified glucosamine (GlcNAc). The azido-sugar is incorporated into intracellular O-GlcNAc-containing glycoproteins through the permissive nature of the oligosaccharide biosynthesis pathway. In step two, via the chemoselective ligation or click reaction between an azide and an alkyne, the azido-labeled glycoproteins can then detected with a Click-iT® Glycoprotein Detection kit for gels (TAMRA or Dapoxyl® alkyne) or Western blots (biotin alkyne). The Click-iT® glycoprotein products are compatible with LC-MS⁄MS and Multiplexed Proteomics™ technologies for in-depth analyses of the glycoproteome.

HABA (4'-hydroxyazobenzene-2-carboxylic acid) (Thermo Scientific™)

Thermo Scientific Pierce HABA is 4'-hydroxyazobenzene-2-carboxylic acid, a simple reagent that enables spectrophotometric (colorimetric) estimation of biotinylation levels of labeled proteins and other molecules.

Features of HABA:

• HABA-avidin complex can be used over a wide range of pH and salt concentrations
• Amount of Avidin can be calculated directly from the increased absorbance at 500nm complexing with the HABA Dye
• Calculate results directly from absorbance values based on extinction coefficients using the procedure outlined in the instructions
• Complete kits also available! See Pierce Biotin Quantitation Kit (Part No. 28005) and Fluorescence Biotin Quantitation Kit (Part No. 46610)

Determine the molar ratio of biotin incorporated into a protein using the HABA-Avidin method. HABA dye (4'-hydroxyazobenzene-2-carboxylic acid ) binds to avidin to produce a yellow-orange colored complex which absorbs at 500nm. Free biotin will displace the HABA dye and cause the absorbance to decrease. A standard curve can be established using the free biotin to estimate the number of moles of biotin incorporated after biotinylating a protein. View online HABA Calculator.

Click-IT™ O-GlcNAc Enzymatic Labeling System (Invitrogen™)

The Click-iT® O-GlcNAc Enzymatic Labeling System provides a highly sensitive and efficient method for the in-vitro modification of O-GlcNAc modified proteins. Proteins are enzymatically labeled utilizing the permissive mutant β-1,4-galactosyltransferase (Gal-T1 (Y289L)) which transfers azido-modified galactose (GalNAz) from UDP-GalNAz to O-GlcNAc residues. Then, via the chemoselective ligation or click reaction between an azide and an alkyne, the azido-labeled glycoproteins can then be detected with a Click-iT® Glycoprotein Detection kit for gels (TAMRA or Dapoxyl® alkyne) or Western blots (biotin alkyne). Labeling and detection can be completed in less than 24 hours and the Click-iT® glycoprotein products are compatible with LC-MS/MS and Multiplexed Proteomics™ technologies for in-depth analyses of this important post-translational modification.

Alexa Fluor™ 555 Protein Labeling Kit (Invitrogen™)

Molecular Probes® Protein Labeling Kits provide a convenient means for attaching a fluorescent label (or biotin) to an antibody (or a protein larger than 40 kDa). Conjugates are ideal for multiple applications, including flow cytometry, fluorescent microscopy, immunohistochemistry, primary detection, ELISAs, immunocytochemistry, FISH, and more. Kits are available in 12 Alexa Fluor® dye colors, biotin, the hapten Oregon Green® 488, fluorescein EX, and Texas Red® dye. Each kit provides the components needed to perform three protein conjugations and purifications.

Important Features of Protein Labeling Kits:

• Labeled proteins typically ready to use in 2 hr (~30 min hands-on time)
• Designed to label 1 mg of IgG
• Simple protocol—react, separate, use
• Stabilizing proteins must be removed from the sample before labeling


The Benefits of Alexa Fluor® Dyes
Compared to traditional dyes, Alexa Fluor® dyes are brighter, more photostable, and more pH resistant between pH 4 and 10. And generally when using Alexa Fluor® dyes, higher degrees of labeling can be achieved without intramolecular quenching. For details see Alexa Fluor® Dyes Spanning the Visible and Infrared Spectrum—Section 1.3.

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 Antibody Labeling from A to Z or use our Labeling Chemistry Selection Tool for other choices. To learn more about our various kits read Kits for Labeling Proteins and Nucleic Acids—Section 1.2 in the Molecular Probes® Handbook.

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.

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.

pHrodo™ iFL Red Microscale Protein Labeling Kit (Invitrogen™)

The pHrodo iFL Red Microscale Protein Labeling Kit provides the reagents needed to easily label 3 microscale purified protein or antibody samples (20–100 µg) with pHrodo iFL Red dye.

The pHrodo iFL Red Microscale Labeling Kit is:
Convenient—labeling typically takes 2 hours with less than 30 min hands-on time
Versatile—label proteins with molecular weights between 12 and 150 kDa
Customizable—create your own probes for studying antibody internalization, phagocytosis, and endocytosis

This kit contains amine-reactive pH-sensitive pHrodo iFL Red STP ester dye that covalently binds to free lysines anywhere they occur in an antibody or protein. pHrodo iFL Red dye is an improved version of pHrodoRed dye optimized for the creation of bright and soluble bioconjugates to be used in the study of antibody internalization, endocytosis, and phagocytosis. It is more soluble than the original pHrodo Red dye, making it useful for the labeling of antibodies that may otherwise precipitate out of solution during conjugation. pHrodo iFL Red dye dramatically increases fluorescence as the pH of its surroundings become more acidic. It is non-fluorescent outside the cell, but fluoresces bright red in phagosomes and endosomes.

EZ-Link™ Micro Sulfo-NHS-LC-Biotinylation Kit (Thermo Scientific™)

The Thermo Scientific EZ-Link Sulfo-NHS-LC-Biotinylation Kit contains reagents sufficient for 8 biotinylation reactions (e.g., 0.05–0.2 mg antibody per reaction). The EZ-Link Sulfo-NHS-LC-Biotin reagent included in the kit is an intermediate-length, water-soluble biotinylation reagent for labeling antibodies, proteins, and other molecules that have primary amines.

Features of EZ-Link Sulfo-NHS-LC-Biotin:

Protein labeling—biotinylate antibodies to facilitate immobilization, purification or detection using streptavidin resins or probes
Cell surface labeling—biotinylates only surface proteins of whole cells because the negatively charged reagent does not permeate cell membranes
Amine-reactive—reacts with primary amines (-NH2), such as lysine side-chains, or the amino-termini of polypeptides
Soluble—charged sulfo-NHS group increases reagent water solubility compared to ordinary NHS-ester compounds
Irreversible—forms permanent amide bonds; spacer arm cannot be cleaved
Medium length—spacer arm (total length added to target) is 22.4 angstroms; provides excellent balance between adequate length (minimal steric hindrance for biotin binding) and modest mass

Sulfo-NHS-LC-Biotin is one of three very similar EZ-Link Reagents that are water-soluble, non-cleavable, and enable simple and efficient biotinylation of antibodies, proteins and any other primary amine-containing macromolecules in solution. Specific labeling of cell surface proteins is another common application for these uniquely water-soluble and membrane impermeable reagents. Differing only in their spacer arm lengths, the three Sulfo-NHS-ester reagents offer the possibility of optimizing labeling and detection experiments where steric hindrance of biotin binding is an important factor. Sulfo-NHS-LC-Biotin is offered in several package sizes and as complete protein labeling kits.

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

N-Hydroxysulfosuccinimide (NHS) esters of biotin are the most popular type of biotinylation reagent. NHS-activated biotins react efficiently with primary amino groups (-NH2) in alkaline buffers to form stable amide bonds. Proteins (e.g., antibodies) typically have several primary amines that are available as targets for labeling, including the side chain of lysine (K) residues and the N-terminus of each polypeptide.

Varieties of biotin NHS-ester reagents differ in length, solubility, cell permeability and cleavability. Non-sulfonated NHS-biotins are cell permeable but must be dissolved in organic solvent such as DMSO or DMF. Sulfo-NHS biotins (and those with pegylated spacers) are directly water soluble but not membrane permeable. Varieties containing disulfide bonds can be cleaved using reducing agents, enabling the biotin group to be disconnected from the labeled protein.

Related Products
EZ-Link™ Sulfo-NHS-LC-Biotin
EZ-Link™ Sulfo-NHS-LC-Biotinylation Kit

Click-IT™ Palmitic Acid, Azide (15-Azidopentadecanoic Acid) (Invitrogen™)

Identify and characterize palmitylated proteins with Click-iT® palmitic acid, azide using the powerful click chemistry, a simple and robust two-step labeling and detection technique. In step one, the azide-containing biomolecule is fed to cells or animals and actively incorporated into proteins. Unlike other labels such as biotin or a fluorescent dye, the azide-tag is small enough that the tagged molecule is an acceptable substrate for the enzymes that incorporate this building block into proteins. Detection utilizes the chemoselective ligation or “click" reaction between and azide and an alkyne where the modified protein is detected with the corresponding alkyne-containing dye or hapten using either the Click-iT® Cell Reaction Buffer Kit or the Click-iT® Protein Buffer Kit. With the Click-iT® Cell Reaction Buffer Kit, cells can be analyzed by fluorescence microscopy, flow cytometry or high-content imaging and analysis (HCS) together with other biomarkers of interest for content and context rich results. With the Click-iT® Protein Reaction Buffer Kit, achieve detection sensitivity in 1-D gels and western blots in the low femtomole range or perform LC-MS⁄MS and MALDI MS analysis.

Alexa Fluor™ 350 Protein Labeling Kit (Invitrogen™)

Molecular Probes® Protein Labeling Kits provide a convenient means for attaching a fluorescent label (or biotin) to an antibody (or a protein larger than 40 kDa). Conjugates are ideal for multiple applications, including flow cytometry, fluorescent microscopy, immunohistochemistry, primary detection, ELISAs, immunocytochemistry, FISH, and more. Kits are available in 12 Alexa Fluor® dye colors, biotin, the hapten Oregon Green® 488, fluorescein EX, and Texas Red® dye. Each kit provides the components needed to perform three protein conjugations and purifications.

Important Features of Protein Labeling Kits:

• Labeled proteins typically ready to use in 2 hr (~30 min hands-on time)
• Designed to label 1 mg of IgG
• Simple protocol—react, separate, use
• Stabilizing proteins must be removed from the sample before labeling

The Benefits of Alexa Fluor® Dyes
Compared to traditional dyes, Alexa Fluor® dyes are brighter, more photostable, and more pH resistant between pH 4 and 10. And generally when using Alexa Fluor® dyes, higher degrees of labeling can be achieved without intramolecular quenching. For details see Alexa Fluor® Dyes Spanning the Visible and Infrared Spectrum—Section 1.3.

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 Antibody Labeling from A to Z or use our Labeling Chemistry Selection Tool for other choices. To learn more about our various kits read Kits for Labeling Proteins and Nucleic Acids—Section 1.2 in the Molecular Probes® Handbook.

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.

EZ-Link™ Sulfo-NHS-LC-Biotinylation Kit (Thermo Scientific™)

The Thermo Scientific EZ-Link Sulfo-NHS-LC-Biotinylation Kit contains reagents sufficient for 10 biotinylation reactions (e.g., 1–10 mg antibody per reaction). The EZ-Link Sulfo-NHS-LC-Biotin reagent included in the kit is an intermediate-length, water-soluble biotinylation reagent for labeling antibodies, proteins, and other molecules that have primary amines.

Features of EZ-Link Sulfo-NHS-LC-Biotin:

Protein labeling—biotinylate antibodies to facilitate immobilization, purification or detection using streptavidin resins or probes
Cell surface labeling—biotinylates only surface proteins of whole cells because the negatively charged reagent does not permeate cell membranes
Amine-reactive—reacts with primary amines (-NH2), such as lysine side-chains, or the amino-termini of polypeptides
Soluble—charged sulfo-NHS group increases reagent water solubility compared to ordinary NHS-ester compounds
Irreversible—forms permanent amide bonds; spacer arm cannot be cleaved
Medium length—spacer arm (total length added to target) is 22.4 angstroms; provides excellent balance between adequate length (minimal steric hindrance for biotin binding) and modest mass

Sulfo-NHS-LC-Biotin is one of three very similar EZ-Link Reagents that are water-soluble, non-cleavable, and enable simple and efficient biotinylation of antibodies, proteins and any other primary amine-containing macromolecules in solution. Specific labeling of cell surface proteins is another common application for these uniquely water-soluble and membrane impermeable reagents. Differing only in their spacer arm lengths, the three Sulfo-NHS-ester reagents offer the possibility of optimizing labeling and detection experiments where steric hindrance of biotin binding is an important factor. Sulfo-NHS-LC-Biotin is offered in several package sizes and as complete protein labeling kits.

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

N-Hydroxysulfosuccinimide (NHS) esters of biotin are the most popular type of biotinylation reagent. NHS-activated biotins react efficiently with primary amino groups (-NH2) in alkaline buffers to form stable amide bonds. Proteins (e.g., antibodies) typically have several primary amines that are available as targets for labeling, including the side chain of lysine (K) residues and the N-terminus of each polypeptide.

Varieties of biotin NHS-ester reagents differ in length, solubility, cell permeability and cleavability. Non-sulfonated NHS-biotins are cell permeable but must be dissolved in organic solvent such as DMSO or DMF. Sulfo-NHS biotins (and those with pegylated spacers) are directly water soluble but not membrane permeable. Varieties containing disulfide bonds can be cleaved using reducing agents, enabling the biotin group to be disconnected from the labeled protein.

Related Products
EZ-Link™ Sulfo-NHS-LC-Biotin
EZ-Link™ Micro Sulfo-NHS-LC-Biotinylation Kit

Biotin-XX Microscale Protein Labeling Kit with FluoReporter™ Biotin Quantitation Assay Kit (Invitrogen™)

Microscale Protein Labeling Kits provide a convenient means for attaching a fluorescent label to a small amount of antibody or protein (20–100 μg). The kits are available in four Alexa Fluor® colors (or biotin) and supply everything needed for three labeling and separation reactions.

Important Features of Microscale Protein Labeling Kits:

• Labeled proteins typically ready to use typically in 2 hr (~30 min hands-on time)
• Optimized for 20–100 μg of protein with molecular weights between 12 and 150 kDa
• Purified using convenient spin filters with yields between 60 and 90%
• Stabilizing proteins must be removed from the sample before labeling


Stable Reaction Chemistry and Superior Alexa Fluor® Dyes
In the Microscale Protein Labeling Kits, the reactive dye contains a tetrafluorophenyl (TFP) ester moiety that is more stable in solution than the commonly used succinimidyl (NHS) ester. TFP esters react efficiently with primary amines of proteins to form stable dye–protein conjugates. Compared to traditional dyes, Alexa Fluor® dyes are brighter, more photostable, and more pH resistant between pH 4 and 10. And generally when using Alexa Fluor® dyes, higher degrees of labeling can be achieved without intramolecular quenching. For details see Alexa Fluor® Dyes Spanning the Visible and Infrared Spectrum—Section 1.3.

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 Antibody Labeling from A to Z or use our Labeling Chemistry Selection Tool for other choices. To learn more about our various kits read Kits for Labeling Proteins and Nucleic Acids—Section 1.2 in the Molecular Probes® Handbook.

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.

Alexa Fluor™ 633 Protein Labeling Kit (Invitrogen™)

Molecular Probes® Protein Labeling Kits provide a convenient means for attaching a fluorescent label (or biotin) to an antibody (or a protein larger than 40 kDa). Conjugates are ideal for multiple applications, including flow cytometry, fluorescent microscopy, immunohistochemistry, primary detection, ELISAs, immunocytochemistry, FISH, and more. Kits are available in 12 Alexa Fluor® dye colors, biotin, the hapten Oregon Green® 488, fluorescein EX, and Texas Red® dye. Each kit provides the components needed to perform three protein conjugations and purifications.

Important Features of Protein Labeling Kits:

• Labeled proteins typically ready to use in 2 hr (~30 min hands-on time)
• Designed to label 1 mg of IgG
• Simple protocol—react, separate, use
• Stabilizing proteins must be removed from the sample before labeling


The Benefits of Alexa Fluor® Dyes
Compared to traditional dyes, Alexa Fluor® dyes are brighter, more photostable, and more pH resistant between pH 4 and 10. And generally when using Alexa Fluor® dyes, higher degrees of labeling can be achieved without intramolecular quenching. For details see Alexa Fluor® Dyes Spanning the Visible and Infrared Spectrum—Section 1.3.

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 Antibody Labeling from A to Z or use our Labeling Chemistry Selection Tool for other choices. To learn more about our various kits read Kits for Labeling Proteins and Nucleic Acids—Section 1.2 in the Molecular Probes® Handbook.

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.

pHrodo™ iFL Green Microscale Protein Labeling Kit (Invitrogen™)

The pHrodo iFL Green Microscale Protein Labeling Kit provides the reagents needed to easily label 3 microscale purified protein or antibody samples (20–100 µg) with pHrodo iFL Green dye.

The pHrodo iFL Green Microscale Labeling Kit is:
Convenient—labeling typically takes 2 hours with less than 30 min hands-on time
Versatile—label proteins with molecular weights between 12 and 150 kDa
Customizable—create your own probes for studying antibody internalization, phagocytosis, and endocytosis

This kit contains amine-reactive pH-sensitive pHrodo iFL Green STP ester dye that covalently binds to free lysines anywhere they occur in an antibody or protein. pHrodo iFL Green dye is an improved version of pHrodoGreen dye optimized for the creation of bright and soluble bioconjugates to be used in the study of antibody internalization, endocytosis, and phagocytosis. It is more soluble than the original pHrodoGreen dye, making it more useful for the labeling of antibodies that may otherwise precipitate out of solution during conjugation. pHrodo iFL Green dye dramatically increases fluorescence as the pH of its surroundings become more acidic. It is non-fluorescent outside the cell, but fluoresces bright red in phagosomes and endosomes.

Alexa Fluor™ 546 Protein Labeling Kit (Invitrogen™)

Molecular Probes® Protein Labeling Kits provide a convenient means for attaching a fluorescent label (or biotin) to an antibody (or a protein larger than 40 kDa). Conjugates are ideal for multiple applications, including flow cytometry, fluorescent microscopy, immunohistochemistry, primary detection, ELISAs, immunocytochemistry, FISH, and more. Kits are available in 12 Alexa Fluor® dye colors, biotin, the hapten Oregon Green® 488, fluorescein EX, and Texas Red® dye. Each kit provides the components needed to perform three protein conjugations and purifications.

Important Features of Protein Labeling Kits:

• Labeled proteins typically ready to use in 2 hr (~30 min hands-on time)
• Designed to label 1 mg of IgG
• Simple protocol — react, separate, use
• Stabilizing proteins must be removed from the sample before labeling


The Benefits of Alexa Fluor® Dyes
Compared to traditional dyes, Alexa Fluor® dyes are brighter, more photostable, and more pH resistant between pH 4 and 10. And generally when using Alexa Fluor® dyes, higher degrees of labeling can be achieved without intramolecular quenching. For details see Alexa Fluor® Dyes Spanning the Visible and Infrared Spectrum—Section 1.3.

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 Antibody Labeling from A to Z or use our Labeling Chemistry Selection Tool for other choices. To learn more about our various kits read Kits for Labeling Proteins and Nucleic Acids—Section 1.2 in the Molecular Probes® Handbook.

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.

EZ-Link™ Sulfo-NHS-Biotinylation Kit (Thermo Scientific™)

The Thermo Scientific EZ-Link Sulfo-NHS-Biotinylation Kit contains reagents sufficient for 10 biotinylation reactions (e.g., 1–10 mg antibody per reaction). The EZ-Link Sulfo-NHS-Biotin reagent included in the kit is a short-chain, water-soluble biotinylation reagent used for labeling antibodies, proteins and other molecules that have primary amines.

Features of EZ-Link Sulfo-NHS-Biotin:

Protein labeling—biotinylate antibodies to facilitate immobilization, purification or detection using streptavidin resins or probes
Cell surface labeling—biotinylates only surface proteins of whole cells because the negatively charged reagent does not permeate cell membranes
Amine-reactive—reacts with primary amines (-NH2), such as lysine side-chains or the amino-termini of polypeptides
Soluble—charged sulfo-NHS group increases reagent water solubility compared to ordinary NHS-ester compounds
Irreversible—forms permanent amide bonds; spacer arm cannot be cleaved
Very short—spacer arm (total length added to target) is 13.5 angstroms; it consists of the native biotin valeric acid group only.

Sulfo-NHS-Biotin is the shortest of three very similar EZ-Link Reagents that are water-soluble, non-cleavable, and enable simple and efficient biotinylation of antibodies, proteins and any other primary amine-containing macromolecules in solution. Specific labeling of cell surface proteins is another common application for these uniquely water-soluble and membrane impermeable reagents. Differing only in their spacer arm lengths, the three Sulfo-NHS-ester reagents offer the possibility of optimizing labeling and detection experiments where steric hindrance of biotin binding is an important factor. Sulfo-NHS-Biotin is offered in several package sizes and as complete protein labeling kits.

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

N-Hydroxysulfosuccinimide (NHS) esters of biotin are the most popular type of biotinylation reagent. NHS-activated biotins react efficiently with primary amino groups (-NH2) in alkaline buffers to form stable amide bonds. Proteins (e.g., antibodies) typically have several primary amines that are available as targets for labeling, including the side chain of lysine (K) residues and the N-terminus of each polypeptide.

Varieties of biotin NHS-ester reagents differ in length, solubility, cell permeability and cleavability. Non-sulfonated NHS-biotins are cell permeable but must be dissolved in organic solvent such as DMSO or DMF. Sulfo-NHS biotins (and those with pegylated spacers) are directly water soluble but not membrane permeable. Varieties containing disulfide bonds can be cleaved using reducing agents, enabling the biotin group to be disconnected from the labeled protein.

Related Products
EZ-Link™ Sulfo-NHS-Biotin
EZ-Link™ Micro Sulfo-NHS-Biotinylation Kit