Our custom fluorescent antibody and protein labeling service combines years of conjugation expertise with a wide selection of labels, including fluorescent dyes, phycobiliproteins, and enzymes, along with a choice of labeling chemistries. We provide conjugation services for both research and commercial use.

Once you have determined your requirements, please download the custom labeling quote form, complete, and email it to the address on the form. For questions, please contact us at

Choose your labeling chemistry

  • Amine labeling—the most common form of labeling; amine reactive dyes are regularly used to label antibodies and other proteins for use in immunochemistry and immunoassays
  • Thiol labeling—this is another option for labeling your protein of interest, if free thiols are present. Depending on the protein, labeling via thiol group may be useful for site specific labeling.
  • SiteClick™ labeling—labeling using click chemistry can introduce the label via sugars found associated with the Fc region of many antibodies
  • Other labeling methods—we also perform labeling utilizing other reactive chemistries, such as labeling a carboxylate and aldehyde groups, or introduce a label using crosslinking chemistries

Choose your label

We can conjugate your antibody or protein to:

  • Alexa Fluor® dyes—for superior fluorescence performance across and beyond the visible spectrum, these dyes can be attached to antibodies and proteins without significant self-quenching, leading to brighter conjugates
  • Qdot® nanocrystals—ideal for experiments requiring long-term photo-stability or single-excitation, multicolor analysis, these fluorescent particles have specially modified surfaces that facilitate conjugation to your protein of interest
  • pHrodo™ Red and pHrodo™ Green pH indicator dyes—these pH sensitive dyes are almost non-fluorescent at neutral pH, but fluoresce brightly in acidic environments
  • Pacific Blue™, Pacific Green™ and Pacific Orange™ dyes—UV excitable dyes specifically created for use with the violet laser found on many flow cytometers
  • R-PE, APC, and Alexa Fluor® dye tandems—traditional fluorescent labels for flow cytometry applications, along with R-PE and APC tandems featuring our Alexa Fluor® dyes
  • Traditional fluorophores and labels—these include biotin, FITC, TRITC, and Texas Red® dye
  • Enzyme labels—choose from among RP, alkaline phosphatase, and others

If you don’t see the label you are interested in, just ask—in most cases, we can accommodate your request.

Other bio-conjugation services
  • Custom Zenon® labelingZenon® labeling technology allows for rapid non-covalent antibody labeling. If you can’t find the Zenon® labeling reagent you need, let us make one for you, with our custom labeling services. Download the custom labeling services quote form, complete, and email to the address on the form.
  • Biopolymer labeling—we can also label certain biopolymers, such as dextrans, with many of the labels listed in the above section.
Frequently asked questions
Where do I send my antibody?

We will assign a quote number to all requests. Instructions on where to send your antibody and which quote number to reference are included in our quotes.

What is the minimum amount of antibody I can send to have labeled?

For best results, we recommend starting with at least 1 mg of material, but can often accommodate smaller conjugations, depending on the protein. Just ask.

Can you order the antibody from my vendor for me?

Yes, but we charge a handling fee to cover our costs and the risks associated with working directly with a vendor of your choice.

Can you purify my antibody for me before labeling?

In many cases we can, for an extra fee. Include the requirement when making a quote request, and we can include the additional service in our quote.

What is the lead time?

In most cases, we can ship product within 15 business days of receiving your antibody and order. Some projects will require additional time.

Custom fluorescent antibody and protein labeling service
Alexa Fluor® Labeling Kits