Brighter insights, precise research

Tell your cell story with Invitrogen’s Antibody Labeling Kits

In addition to exceptional brightness and photostability, our customers can get access to an experienced, problem-solving technical support team, application and experimental tips, and protocols to help with experimental planning.

Not sure which type of conjugation kit to use? Explore the table and sections below to find the best type of antibody conjugation kit for your application.

Which antibody labeling kit do you need?

These kits have quick protocols and conjugates that are ready in 15 minutes or less.

 Zip Rapid Antibody Labeling KitsZenon Antibody Labeling Kits
Amount IgG labeled/reaction*100 µg1–20 µg
Label target/methodFree lysines/covalent amine-reactive chemistryFc portion of IgG/antibody affinity
Can measure degree of labeling?NoNo
Can store conjugate more than 24 hr?YesNo
Site-specific label?NoNo
Compatible with BSA or other stabilizers in sample buffer?NoYes
Requires post-label purification?NoNo
Time required for protocol15 min5 min
Optimal applications**FC, IF, WB, HCAFC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

These kits use conventional amine-reactive dyes that covalently label primary amines on an antibody.

 Standard Amine Reactive Antibody Labeling KitsZip Rapid Antibody Labeling KitsLarge Scale Antibody Labeling KitsReadyLabel Antibody Labeling Kits
Amount IgG labeled/reaction*100 µg100 µg1 mg20 or 100 µg
Label target/methodFree lysines/covalent amine-reactive chemistry
Can measure degree of labeling?YesNoYesYes
Can store conjugate more than 24 hr?YesYesYesYes
Site-specific label?NoNoNoNo
Compatible with BSA or other stabilizers in sample buffer?NoNoNoYes
Requires post-label purification?Yes - includedNoYes - includedYes - included
Time required for protocol60 min15 min60 min60 min
Optimal applications**FC, IF, WB, HCAFC, IF, WB, HCAFC, IF, WB, HCAFC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

These methods prevent labeling of the antigen binding site.

 SiteClick Antibody Labeling Kits
Amount IgG labeled/reaction*100 µg–5 mg
Label target/methodCarbohydrates on IgG heavy chain/covalent, copper-free click chemistry
Can measure degree of labeling?Yes
Can store conjugate more than 24 hr?Yes
Site-specific label?Yes
Compatible with BSA or other stabilizers in sample buffer?Yes
Requires post-label purification?Yes - included
Time required for protocolovernight incubation
Optimal applications**FC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

Antibody labeling kits to rapidly screen for the binding of therapeutic antibodies

 Zenon Antibody Labeling KitsReadyLabel Antibody Labeling Kits
Amount IgG labeled/reaction*1–20 µg (96 labelings) 20 or 100 µg (5 labelings) 
Label target/methodFc portion of IgG/antibody affinityFree lysines/covalent amine-reactive chemistry
Can measure degree of labeling?NoYes
Can store conjugate more than 24 hr?NoYes
Site-specific label?NoNo
Compatible with BSA or other stabilizers in sample buffer?YesYes
Requires post-label purification?NoYes—included
Time required for protocol5 min60 min
Optimal applications**FC, IF, WB, HCAFC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

pHrodo dyes are nonfluorescent at neutral pH and become brightly fluorescent in the acidic environment as they are internalized.

 pHrodo Antibody Labeling Kits SiteClick pHrodo Antibody Labeling Kits Zenon pHrodo Antibody Labeling Reagents
Amount IgG labeled/reaction*20 µg–1 mg100 µg–5 mg1–20 µg
Label target/methodFree lysines/covalent amine-reactive chemistryFc portion of IgG/antibody affinityFc portion of IgG/antibody affinity
Can measure degree of labeling?YesYesNo
Can store conjugate more than 24 hr?YesYesNo
Site-specific label?NoYesNo
Compatible with BSA or other stabilizers in sample buffer?NoYesYes
Requires post-label purification?Yes—includedYes—includedNo
Time required for protocol60 minOvernight incubation5 min
Optimal applications**FC, IF, WB, HCAFC, IF, WB, HCAFC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

These kits have quick protocols and conjugates that are ready in 15 minutes or less.

 Zip Rapid Antibody Labeling KitsZenon Antibody Labeling Kits
Amount IgG labeled/reaction*100 µg1–20 µg
Label target/methodFree lysines/covalent amine-reactive chemistryFc portion of IgG/antibody affinity
Can measure degree of labeling?NoNo
Can store conjugate more than 24 hr?YesNo
Site-specific label?NoNo
Compatible with BSA or other stabilizers in sample buffer?NoYes
Requires post-label purification?NoNo
Time required for protocol15 min5 min
Optimal applications**FC, IF, WB, HCAFC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

These kits use conventional amine-reactive dyes that covalently label primary amines on an antibody.

 Standard Amine Reactive Antibody Labeling KitsZip Rapid Antibody Labeling KitsLarge Scale Antibody Labeling KitsReadyLabel Antibody Labeling Kits
Amount IgG labeled/reaction*100 µg100 µg1 mg20 or 100 µg
Label target/methodFree lysines/covalent amine-reactive chemistry
Can measure degree of labeling?YesNoYesYes
Can store conjugate more than 24 hr?YesYesYesYes
Site-specific label?NoNoNoNo
Compatible with BSA or other stabilizers in sample buffer?NoNoNoYes
Requires post-label purification?Yes - includedNoYes - includedYes - included
Time required for protocol60 min15 min60 min60 min
Optimal applications**FC, IF, WB, HCAFC, IF, WB, HCAFC, IF, WB, HCAFC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

These methods prevent labeling of the antigen binding site.

 SiteClick Antibody Labeling Kits
Amount IgG labeled/reaction*100 µg–5 mg
Label target/methodCarbohydrates on IgG heavy chain/covalent, copper-free click chemistry
Can measure degree of labeling?Yes
Can store conjugate more than 24 hr?Yes
Site-specific label?Yes
Compatible with BSA or other stabilizers in sample buffer?Yes
Requires post-label purification?Yes - included
Time required for protocolovernight incubation
Optimal applications**FC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

Antibody labeling kits to rapidly screen for the binding of therapeutic antibodies

 Zenon Antibody Labeling KitsReadyLabel Antibody Labeling Kits
Amount IgG labeled/reaction*1–20 µg (96 labelings) 20 or 100 µg (5 labelings) 
Label target/methodFc portion of IgG/antibody affinityFree lysines/covalent amine-reactive chemistry
Can measure degree of labeling?NoYes
Can store conjugate more than 24 hr?NoYes
Site-specific label?NoNo
Compatible with BSA or other stabilizers in sample buffer?YesYes
Requires post-label purification?NoYes—included
Time required for protocol5 min60 min
Optimal applications**FC, IF, WB, HCAFC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

pHrodo dyes are nonfluorescent at neutral pH and become brightly fluorescent in the acidic environment as they are internalized.

 pHrodo Antibody Labeling Kits SiteClick pHrodo Antibody Labeling Kits Zenon pHrodo Antibody Labeling Reagents
Amount IgG labeled/reaction*20 µg–1 mg100 µg–5 mg1–20 µg
Label target/methodFree lysines/covalent amine-reactive chemistryFc portion of IgG/antibody affinityFc portion of IgG/antibody affinity
Can measure degree of labeling?YesYesNo
Can store conjugate more than 24 hr?YesYesNo
Site-specific label?NoYesNo
Compatible with BSA or other stabilizers in sample buffer?NoYesYes
Requires post-label purification?Yes—includedYes—includedNo
Time required for protocol60 minOvernight incubation5 min
Optimal applications**FC, IF, WB, HCAFC, IF, WB, HCAFC, IF, WB, HCA
*Kits are optimized for whole IgG protein, molecular weight 150 kDa unless otherwise indicated. For those kits, please see instructions on how to adjust protein concentration for optimal dye:protein ratios.
**FC=flow cytometry; IF=immunofluorescence; WB=western blot analysis; HCA=high content analysis

Not looking for a kit or need a different dye?

For flow cytometry antibody conjugation, see the NovaFluor Dyes for Immunophenotyping which are designed for more resolution with narrow emission spectra and minimal cross-laser excitation.

Find DyLight antibody labeling kits for labeling 1 mg or 100 μg of antibody with DyLight fluorophores across the spectrum.

Find standalone amine-reactive dyes and more information about amine-reactive chemistries in Fluorophores and Their Amine-Reactive Derivatives—Chapter 1, The Molecular Probes Handbook.

We also have thiol-reactive dyes available as standalone reagents and you can learn more about these in the Thiol-Reactive Probes—Chapter 2, The Molecular Probes Handbook.

Amine-Reactive Antibody Labeling Kits

Zip Rapid Antibody Labeling Kits

Zip Rapid Antibody Labeling Kits

Zip Alexa Fluor Rapid Antibody Labeling Kits allow you to efficiently label your precious antibody with fluorescent dyes to create an antibody conjugate that is ready to use within 15 minutes.

  • Label 100 μg of IgG antibody
  • Three labeling reactions per kit
  • Very fast and easy to use
  • 100% antibody recovery—no purification steps
  • No chemistry or conjugation experience needed

The kit contains everything you need to perform three separate labeling reactions. Covalently labeled conjugates are exceptional for multiple applications, including flow cytometry, fluorescence microscopy, immunohistochemistry, primary antibody detection, ELISAs, immunocytochemistry, and indirect FISH. Simply add 1 mL water to component A containing Zip buffer, add 1 mg of antibody, incubate for 15 minutes, and your antibody is ready to use (Figure 1).

Zip Rapid Antibody Labeling Kits selection guide

LabelEx/Em*Cat. No.
Alexa Fluor 488494/519Z11233
Alexa Fluor 555555/565Z11234
Alexa Fluor 647650/668Z11235

Ex/Em = Fluorescence excitation and emission maxima, in nm.

Find more information about Alexa Fluor dyes and other fluorophores in the Fluorophore Selection Guide


Standard Amine-Reactive Antibody Labeling Kits

Standard Amine-Reactive Antibody Labeling Kits

Thermo Fisher Scientific Standard Amine-Reactive Antibody Labeling Kits label 100 µg IgG polyclonal and monoclonal antibodies with our exceptional Alexa Fluor, Pacific Blue, or Pacific Orange dyes.

  • Label 100 µg
  • Five labeling reactions per kit
  • Labeled antibodies ready in 90 minutes
  • ~15 minutes actual hands-on time
  • Requires removal of BSA and other protein stabilizers prior to labeling reaction

The Antibody Labeling Kits utilize an amine-reactive Alexa Fluor, Pacific Blue or Pacific Orange fluorophore to covalently attach the label to the IgG antibody of interest. Once formed, the covalent bond between the label and the protein is extremely stable and you are using the same chemistry we use to prepare our own primary and secondary conjugates.

These kits are optimized for labeling 100 µg of antibody per reaction. Simply adjust the protein concentration to ~1 mg/mL in the provided buffer, then add it to a vial of amine-reactive dye. Any stabilizing proteins (e.g., BSA) must be removed prior to the labeling reaction.

Purification is accomplished on a size exclusion spin column optimized for ≥40 kDa proteins (Figure 2). The entire labeling and purification procedure can be completed in as little as 90 minutes; everything needed to perform five conjugations is provided.

How Antibody Labeling Kits work
Figure 2. Overview of Antibody Labeling Kits process. Simply adjust the protein concentration to ~1 mg/mL in the provided buffer, then add it to a vial of amine-reactive dye. Purification is accomplished on a size exclusion spin column optimized for ≥40 kDa proteins.

Antibody Labeling Kits selection guide

Ex/Em = Fluorescence excitation and emission maxima, in nm.

Find more information about Alexa Fluor dyes and other fluorophores in the Fluorophore Selection Guide

ReadyLabel Antibody Labeling Kits

EVOS M7000 imaged Human Colon Tissue fluorescently labeled with ReadyLabel Antibody Labeling kits

Invitrogen ReadyLabel Antibody Labeling Kits redefine what it means to be “conjugation-ready” by providing an easy-to-use conjugation kit for labeling antibodies in presence of impurities like BSA and other protein stabilizers.

  • Label 20 μg or 100 μg of IgG antibody 
  • 5 labeling reactions per kit
  • Labeled antibodies ready in 60 minutes
  • ~20 minutes of actual hands-on time 
  • No antibody purification step needed
  • Single or multiplex staining

ReadyLabel Antibody Labeling Kits allow for fast, convenient antibody conjugation of off-the-shelf antibodies and cell culture supernatants without prior purification of the antibody solution. This works because the provided ReadyLabel spin columns contain resin that filter out contaminating stabilizer proteins present in the antibody solution (Figure 3). The resulting covalently bonded antibody conjugate can be used with flow cytometry, western blotting, ELISA, and indirect FISH.

ReadyLabel Kits are equipped with your choice of our most popular stains (Alexa Fluor™ 488, Alexa Fluor™ 647, and biotin) to produce high yields of bright, soluble conjugates. Need a different dye? Consider our ReadyLabel Flex Kits which contain everything needed except the dye, and use a dye of your choice. All our ReadyLabel kits are available in two different pack sizes, designed for labelings of 20 μg and 100 μg of IgG per reaction, and include all components necessary for five labeling reactions.

How ReadyLabel Kits work:  ReadyLabel resin-containing spin columns capture BSA and other stabilizing proteins and remove them from the antibody solution
Figure 3. Antibodies are often stored with BSA or other protein stabilizers to prevent degradation. ReadyLabel Kits are equipped with resin-containing spin columns that capture these contaminants and allow you to skip the purification step of your antibody solution. With approximately 20 minutes of hands-on time, and 30 minutes of incubation at room temperature, your covalently bonded antibody conjugate is now ready to use.

ReadyLabel multiplexing capabilities:

ReadyLabel Antibody Labeling Kits offer a unique advantage for multiplexing experiments. Unlike secondary detection methods, which are often constrained by the number of available IgG species, our kits allow you to directly conjugate your primary antibodies. This means you can achieve higher levels of multiplexing with greater flexibility.

Designed with high-quality, bright dyes and a focus on minimizing background noise, our kits enable clear and precise signals in your experiments. This clarity enhances the reliability and accuracy of your results, making ReadyLabel Antibody Labeling Kits well suited for multiplexing applications.

Multiplexed image of human tonsil tissue stained with primary antibodies conjugated using ReadyLabel Kits, showing individual conjugate stains.

Figure 4. FFPE Human Tonsil Tissue is stained with three primary antibodies conjugated using ReadyLabel Kits: CD45RB-Alexa Fluor 488 ReadyLabelTM conjugate, CD68-Alexa Fluor 594 ReadyLabelTM conjugate (using Alexa Fluor 594 NHS Ester with our ReadyLabelTM Flex Antibody Labeling Kit), PCNA-Alexa Fluor 647 ReadyLabelTM conjugate.

How to: ReadyLabel Antibody Labeling Kits Protocol

Ordering information for ReadyLabel


Invitrogen ReadyLabel Antibody Labeling Kit


Large-Scale Antibody Labeling Kits

Protein Labeling Kits

Thermo Fisher Scientific Large-Scale Antibody or Protein Labeling Kits provide a nearly effortless way to covalently label 1 mg of IgG antibody with a fluorescent dye (including Alexa Fluor dyes) or biotin.

  • Label 1 mg antibody
  • 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 2 hours
  • ~ 30 minutes actual hands-on time

TheLarge-Scale Antibody or Protein Labeling Kits utilize an amine-reactive fluorophore or hapten to covalently attach the label to the 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 of purified IgG (in ~500 μL and free of amine-containing buffers such as Tris) to one of the vials containing a premeasured quantity of amine-reactive dye and a magnetic stir bar. Purification is accomplished by a pre-packed spin column supplied with the kit and affords high antibody recovery (typically >85%). The entire labeling and purification procedure can be completed in as little as 90 minutes (approximately 15 mins hands-on time). Removal of free dye is essential for the determination of the degree of labeling (DOL). Everything needed to perform three conjugations is provided.

Large-Scale Antibody or Protein Labeling Kits selection guide

Ex/Em = Fluorescence excitation and emission maxima, in nm.

Find more information about Alexa Fluor dyes and other fluorophores in the Fluorophore Selection Guide


Affinity Antibody Labeling Kits

Zenon Antibody Labeling Kits

Microscope image of fluorescently labeled SKBR3 Cells

Invitrogen Zenon labeling technology rapidly conjugates antibodies to a variety of fluorochromes, even from minimal, unpurified sources like hybridoma culture supernatant. Designed to bind to the Fc portion of primary antibodies, Zenon fragments enable specific, noncovalent labeling of small antibody quantities without compromising antibody function. Zenon Alexa Fluor Plus labeling reagents merge Zenon technology's speed and scalability with the excellent performance of Alexa Fluor Plus dyes, offering an optimal system for screening antibody binding in therapeutic antibody discovery.

  • 5-minute incubation time
  • 1–20 µg primary antibody per labeling
  • Compatible with BSA and other stabilizing proteins
  • No purification step
  • Enables rapid screening of antibody binding
  • Preserves primary antibody function

Invitrogen Zenon labeling reagents provide a quick and easy-to-use system to noncovalently label human, mouse, and rabbit IgG antibodies with a variety of fluorophores. Prelabeled Zenon Fab fragments are designed to rapidly bind to the Fc portion of IgG antibodies, preserving antibody function. Zenon Fab-antibody conjugation occurs in less than 5 minutes, with only a small amount of starting material needed and no purification steps required.

Using Zenon labeling reagents for rapid screening of antibody binding

The new Invitrogen Zenon Alexa Fluor Plus labeling reagents have been optimized to screen for antibody binding, giving a bright fluorescence-based indication of antibody binding. These reagents combine the rapid and scalable Zenon technology with the superior Alexa Fluor Plus fluorophores to provide a higher signal to noise ratio and to increase confidence in your screening results.

Want to learn more about screening for binding of therapeutic antibodies?
View our Scientific Poster for Antibody Labeling Reagents for Therapeutic Antibody Screening

Zenon antibody labeling kits for antibody binding

Interested in screening for antibody internalization instead?
See Zenon pHrodo Labeling Reagents


Zenon antibody labeling kits for multiplex immunofluorescence

ReactivityTarget isotypeFind products
MouseIgG1See all kits
HumanIgGSee all kits
RabbitIgGSee all kits

Site-Specific Antibody Labeling Kits

Click chemistry labeling with SiteClick Antibody Labeling Kits

Drawing of an antibody with Alexa Fluor Dye attaching to Fc region of the antibody using site-click reaction.

Thermo Fisher Scientific SiteClick Labeling Kits allow simple and gentle site-selective attachment of detection molecules to heavy chain N-linked glycans—far from the antigen-binding domain—providing excellent reproducibility from labeling to labeling and from antibody to antibody. A number of different detection molecules can be site-selectively attached to the heavy chain glycans—including phycobiliproteins (e.g., R-PE), QDot probes, Alexa Fluor dyes, pHrodo dye, metal-chelating compounds, and other small molecules like biotin—allowing multiplex analysis with antibodies from the same species. Features include:

  • Labeling of 100 μg up to 5 mg of antibody
  • Easy to follow step-by-step protocol
  • Highly efficient, site-specific, reproducible labeling chemistry
  • Kits and dyes available in a flexible format for easy design of multi-color experiments

In general, IgG antibodies contain two N-linked glycans attached to specific conserved asparagine residues located in the antibody heavy chain Fc domain. These sugar chains, predominantly complex biantennary glycans with two terminal branches, are structurally quite homogeneous, and the terminal sequences of the glycan branches are highly consistent. Most of the antibody glycan branches terminate with galactose-N-acetylglucosamine (Gal-GlcNAc-) or with N-acetylglucosamine (GlcNAc-). Removal of the terminal Gal residue with β-galactosidase unmasks the majority of terminal GlcNAc labeling sites for the subsequent enzymatic β-galactosyl transferase (GalT) reaction (Figure 8). After cleavage of terminal Gal residues by β-galactosidase, each N-linked glycan will contain, on average, 2 terminal GlcNAc residues per heavy chain (4 terminal GlcNAc per antibody). The azide-activated antibody can now be labeled with a dibenzocyclooctyne (DIBO)-functionalized probe using copper-free click chemistry (Figure 9).

How to site-specifically label your antibody using SiteClick Technology

This video explains how to easily and site specifically label an antibody using an enzymatic and Click chemistry approach. This method can be applied to any intact IgG antibody and requires no antibody engineering or complex methodology.

Figure 8. The SiteClick Antibody Labeling Kits overview. The first step in the SiteClick antibody labeling process involves removal of terminal galactose residues from the heavy chain N-linked glycans of the antibody using β-galactosidase, exposing essentially all possible modifiable GlcNAc residues. Second, the free terminal GlcNAc residues are activated with azide tags by enzymatic attachment of GalNAz to the terminal GlcNAc residues using the GalT(Y289L) enzyme. In the third step, the azide residues are reacted with the dibenzocyclooctyne (DIBO)-functionalized probe of choice (e.g., Alexa Fluor 488 sDIBO alkyne) (see Figure 10 for this reaction). The average degree of labeling is 3–3.5 labels per antibody.
Copper-less click chemistry azide/DIBO reaction
Figure 9. Copper-less click chemistry azide/DIBO reaction. The azide and alkyne moieties are interchangeable. The molecule can be labeled with a DIBO and reacted with a fluorophore or hapten-azide.

The SiteClick method is compatible with antibodies from a number of different species including, but not limited to, human, rabbit, mouse, rat, goat, hamster, and chicken. Additionally, SiteClick labeling is effective with several antibody classes such as IgG, IgM, and IgY; note that chicken IgY antibodies have 6 heavy chain glycans instead of 2 and therefore can be labeled to a higher extent.

SiteClick antibody labeling system offers flexibility

The SiteClick Antibody Labeling system is available in two formats:

  • Kits that contain both the azido modification components for preparing the antibody and a sDIBO alkyne to label the antibody (complete reaction featured in Figure 8A and B).
  • A kit that contains only the azido modification component (the first 2 steps of the reaction depicted in Figure 8A).
  • A variety of standalone sDIBO alkyne reagents that can be used to label the modified antibody (step in Figure 8B).

This flexibility of formats allows several advantages including the ability to easily change the fluorescent dye used, without impacting the degree of labeling of the same antibody and the ability to prepare a large batch of modified antibody and label only a small amount as needed, again, preserving the consistency of degree of labeling and functionality.

Antibody functionality is highly preserved

The covalent and site-specific attachment of the dyes to the N-linked glycans on the antibody heavy chain Fc domain ensures the immunogenicity of the antigen binding site is preserved, resulting in more efficient binding to the antigen as compared to antibodies randomly labeled with amine-reactive dyes. In a side-by-side comparison of SiteClick-labeled and amine-reactive labeled anti-troponin 1 antibody, the sensitivity of the SiteClick-labeled antibody was greater than that of the amine-reactive labeled antibody (Figure 10).

Lot-to-lot consistency in antibody degree of labeling

Labeling antibodies with the SiteClick antibody labeling system gives you confidence that the antibody will be labeled the same way every time, with no time needed for reaction optimization. This means the same number of dyes attached to each molecule, the same preservation of the antigen binding site, providing in the same results every time. An example of the consistency in labeling between different antibodies is shown in Figure 11.

Table 1. Antigenicity of primary antibodies labeled in degree of labeling study (Figure 11).

Human IgG1Human IgG3Mouse IgG1Mouse IgG2aGoat Polyclonal
EGFRLymphoma cellGD2CD4Apolipoprotein-A2
HER2/neuGD3β-tubulinCD3 
sLeasLeaCD8aCD8 
GD2f-GM1CD45CD56 
GM2TnC3b, iC3bC3b, iC3b, C3dg 
J591 Interferon-γ  

SiteClick Antibody Labeling Kits selection guide

Product nameAntibody quantity labeledEx/Em*Cat. No.
Kits for antibody modification only
SiteClick Azido Modification Kit100 μgN/AS20026
1 mgS10900
5 mgS10901
Standalone labeling reagents
SiteClick Alexa Fluor 488 sDIBO Alkyne100 μg495/519C20027
1 mgS10904
5 mgS10909
SiteClick Alexa Fluor 555 sDIBO Alkyne100 μg555/565C20028
SiteClick Alexa Fluor 647 sDIBO Alkyne100 μg650/665C20029
1 mgS10906
5 mgS10911
SiteClick iFL pHrodo Red sDIBO Alkyne100 μg560/585C20034
1 mgS10903
5 mgS10908
SiteClick iFL pHrodo Deep Red sDIBO Alkyne100 μg640/655S10914
1 mgS10915
SiteClick Biotin sDIBO Alkyne100 μgN/AC20030
1 mgS10902
5 mgS10907
SiteClick Amine sDIBO Alkyne100 μgN/AC20031
Kits containing antibody modification + labeling reagent
SiteClick R-PE Antibody Labeling kit100 μg565/578S10467
SiteClick Qdot 525 Antibody Labeling kit100 μg405/525S10449
SiteClick Qdot 565 Antibody Labeling kit100 μg405/565S10450
SiteClick Qdot 585 Antibody Labeling kit100 μg405/585S10451
SiteClick Qdot 605 Antibody Labeling kit100 μg405/605S10469
SiteClick Qdot 625 Antibody Labeling kit100 μg405/625S10452
SiteClick Qdot 655 Antibody Labeling kit100 μg405/655S10453
SiteClick Qdot 705 Antibody Labeling kit100 μg405/705S10454
SiteClick Qdot 800 Antibody Labeling kit100 μg405/800S10455
SiteClick Biotin Antibody Labeling Kit100 μgN/AS20033

*Ex/Em = Fluorescence excitation and emission maxima, in nm.
Find more information about Alexa Fluor dyes and other fluorophores in the Fluorophore Selection Guide

For Research Use Only. Not for use in diagnostic procedures.

For Research Use Only. Not for use in diagnostic procedures.