For over 37 years Jackson ImmunoResearch have specialised in the manufacture of secondary antibodies, conjugates and purified immunoglobulins. Their products are made by scientists for scientists and are considered by many to be the gold standard. With their state of the art production facility in rural Pennsylvania and their European hub in Cambridgeshire they serve Research Institutes and Universities throughout the world.

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Technical Centre

Download the JIR Catalogue, Product Handouts, White Papers and Posters

New! Anti-Camelid Secondary Antibodies

At Jackson ImmunoResearch, our mission is to develop the widest range of high quality secondary antibodies for the life science community. To support the growing adoption of camelid-derived heavy chain variable domain (VHH) technologies in a multitude of applications, including next-generation immunotherapeutics, medical imaging, analytical and diagnostic assay development and research discovery, JIR offers three new secondary antibody specificities for detection and quantification of camelid antibodies.

Immunoglobulins Poster

Download our guide to Immunoglobulins Structure and Function

Multiple Labelling Poster

Download our guide to Multiple Labeling with Secondary Antibodies



See JIR Secondary antibodies in action

Contact for more information on any of the following images.

Anti-Alpaca IgG and VHH domain Secondary Antibodies

Find out about our Secondary Antibodies

Mouse on Mouse Labeling with Fab Fragment Blocking

Anti-Camelid Secondary Antibodies

Having manufactured and supplied secondary antibodies and related reagents for 34 years, Jackson ImmunoResearch know the best practices to employ, as well as the pitfalls to be avoided in their use. In these articles we offer the benefit of our experience with useful and practical advice.

Featured Products

Product Code Product Description
115-545-003 Alexa Fluor® 488-AffiniPure Goat Anti-Mouse IgG (H+L)
115-035-003 Peroxidase-AffiniPure Goat Anti-Mouse IgG (H+L)
115-545-166 Alexa Fluor® 488-AffiniPure Goat Anti-Mouse IgG (H+L) (min X Hu,Bov,Hrs,Rb,Rat Sr Prot)
715-545-151 Alexa Fluor® 488-AffiniPure Donkey Anti-Mouse IgG (H+L) (min X Bov,Ck,Gt,GP,Sy Hms,Hrs,Hu,Rb,Rat,Shp Sr Prot)
715-035-151 Peroxidase-AffiniPure Donkey Anti-Mouse IgG (H+L) (min X Bov,Ck,Gt,GP,Sy Hms,Hrs,Hu,Rb,Rat,Shp Sr Prot)
111-545-003 Alexa Fluor® 488-AffiniPure Goat Anti-Rabbit IgG (H+L)
111-035-003 Peroxidase-AffiniPure Goat Anti-Rabbit IgG (H+L)
111-545-144 Alexa Fluor® 488-AffiniPure Goat Anti-Rabbit IgG (H+L) (min X Hu,Ms,Rat Sr Prot)
111-035-144 Peroxidase-AffiniPure Goat Anti-Rabbit IgG (H+L) (min X Hu,Ms,Rat Sr Prot)
711-545-152 Alexa Fluor® 488-AffiniPure Donkey Anti-Rabbit IgG (H+L) (min X Bov,Ck,Gt,GP,Sy Hms,Hrs,Hu,Ms,Rat,Shp Sr Prot)
711-035-152 Peroxidase-AffiniPure Donkey Anti-Rabbit IgG (H+L) (min X Bov,Ck,Gt,GP,Sy Hms,Hrs,Hu,Ms,Rat,Shp Sr Prot)

We can manufacture and supply most standard inventory secondary antibodies in bulk volumes upon request.

Find out more about Bulk Services below;

We can manufacture and supply most standard inventory secondary antibodies in bulk volumes upon request.

The combination of our experience, our focus on Secondary Antibodies and our core principle of manufacturing to the highest quality standards, ensures that customers can be completely confident of product quality, consistency and minimal lot to lot variation over the long-term. These factors contribute to the efficiency of sample evaluations and approval of bulk materials, and to our goal of providing the highest quality of service.

Jackson ImmunoResearch Laboratories, Inc. is certified by BSI to ISO 9001:2015 under certificate number FM 545248.

Our Expertise

  • Over 30 years of experience in a single, highly specialized field; Secondary Antibody and Conjugate manufacture and supply
  • Long-term customer relationships as an established and reliable supplier
  • Fast, efficient customer services
  • Maintaining the highest standards in our research, manufacturing and all operations, which contribute to ensuring guaranteed product quality, long term product consistency and reliable performance.

Our Antibodies and Related Products

We manufacture the most comprehensive range of secondary antibodies and related products. Antibodies are raised in a selection of host species and directed against a wide variety of species and immunoglobulin regions.

All our antibodies are available unconjugated, or conjugated to enzymes (HRP and alkaline phosphatase), a wide range of fluorophores, as well as biotin.

Whole IgG Secondary Antibodies

Specificities include:

  • Whole Ig
  • F(ab’)2 region
  • Fc portion and subclasses
  • Light chain

F(ab’)2 Fragment Secondary Antibodies

Fc region is removed, avoiding binding to live cells with Fc receptors, Protein A or Protein G.

Fab Fragment Secondary Antibodies

Monovalent antibodies for blocking or multiple labeling involving primary antibodies from the same host.

Purified Serum Proteins

For use as experimental controls.

Normal Serums

Blocking agent to reduce background from non-specific, conserved sequence, and/or Fc receptor binding.

Terms of Sale

  • Quotation: JIRE will issue an official quotation including product quantity, pricing, and delivery terms.
  • Order Confirmation: Receipt of the order by JIRE is confirmation of acceptance of terms. An order confirmation from the customer must be received in writing.
  • Purchase Requirements: Customer agrees to purchase and accept shipment of listed quantity at the quoted price. Minimum order quantities apply.
  • Standing Orders: Standing orders are accepted with pre-set ship dates. The customer agrees to purchase the entire quantity of the standing order. There can be no changes to quantity and shipment dates, unless agreed to by JIRE. Each standing order is valid for no more than 12 months from order date unless approved by JIRE.
  • Packaging and Fill Volume: In the event the packaging fill volume differs from Jackson ImmunoResearch Labs, Inc (JIR) standard product fill volume, JIR will provide, on request, samples of the product. Customer agrees to purchase samples at quoted price. Upon sample approval, JIR will deliver the quoted bulk quantity. Customer agrees that the bulk quantity is not eligible for returns or refunds.
  • Product Performance: Upon product acceptance, customer assumes responsibility for product performance.
  • Terms of use: Products are designed for research use only. Customer is responsible for qualifying products for intended use.
  • Additional Terms: JIR will make every attempt to meet expedited requests regardless of the scheduled release date within the limits of material availability and capacity.
  • Payment terms: To be agreed


1. How do you determine protein concentration?

Jackson ImmunoResearch uses the Biuret assay to determine protein concentration.
If protein concentration is obtained by using the mass extinction coefficient of 1.4 for a 1 mg/ml solution at OD280, the result will be 10-15% lower than the concentration obtained by the Biuret assay.

2. What is the molecular weight of my product?

Jackson ImmunoResearch does not determine molecular weights by analytical methods. An approximate molecular weight of 160, 110 and 50 kDa can be used for whole IgG, F(ab’)2 and Fab fragment antibodies, respectively. To obtain an estimated molecular weight of any other product of interest, please contact Technical Service at

3. Do you make custom antibodies?

For purchase of OEM products that have custom specifications (e.g. custom adsorptions, conjugations), please contact Technical Service at Jackson ImmunoResearch does not provide polyclonal or monoclonal antibody development or production services.

4. Are your products endotoxin-free?

Jackson ImmunoResearch does not assay products for endotoxin content. For applications requiring low endotoxin consider using an endotoxin removal column, available from Thermo Fisher, Charles River Laboratories, and other suppliers.

5. Why is there a discrepancy regarding the protein concentration, volume of dH2O used to reconstitute the lyophilized powder, and the nominal fill size reported on the spec sheet?

For products that are sold by weight (mg), Jackson ImmunoResearch fills vials with slightly more product that the nominal mg amount (“Size” on the spec sheet). To calculate the actual product amount in a vial, multiply the protein concentration indicated on the spec sheet by the volume of dH2O needed to rehydrate the lyophilized pellet.

1. What are common causes of background?

Background may be caused by the primary antibody. Perform a control experiment excluding the primary antibody to isolate the secondary antibody as the cause of background.
Improper blocking of the tissues or cells.
Cross-reactivity of the labeled secondary antibodies with endogenous immunoglobulins on the tissues or cells.
Inadequate washing.
Reactivity of the labeled secondary antibody with immunoglobulins in the diluent.
Not diluting the secondary antibodies far enough.

2. What are some causes of weak signal?

There is insufficient antigen present and an amplification protocol may be needed.
Change from a more sensitive detection method to a less sensitive detection method.
The primary antibody is diluted too far.
Enzyme activity is inhibited.
The secondary antibody does not recognize certain primary antibodies well.
The secondary antibody cross-reacts with immunoglobulins in the diluent.

3. What diluent is recommended for the secondary antibody?

The antibodies can be diluted in buffers such as PBS or TBS. A detergent such as Tween 20 (0.05% v/v) can be included to reduce non-specific binding. We recommend making the working dilution fresh on the day of use. Carrier proteins such as BSA or normal serum are not necessary, and in some cases can increase background staining due to protein-protein interactions.
Read more about diluents in our guide to blocking, controls and diluents.

4. What blocking buffer is recommended?

For most applications, we recommend blocking with normal serum (5% v/v) from the same species as the host of the secondary antibody. Other commonly used reagents such as BSA and non-fat dry milk are suitable for some applications, but may increase background if the secondary antibody is directed against goat, sheep, or horse.
Read more about blocking in our guide to blocking, controls and diluents.

5. What incubation time is recommended for the secondary antibody?

Incubation times of 30-60 minutes are recommended for surface interactions such as ELISA or Western blotting. For staining tissue, incubation times should be increased as necessary to allow for tissue penetration. Total wash time should be approximately equal to incubation time to allow unreacted antibody to diffuse out.

1. What is an antibody subclass?

Immunoglobulin classes (IgA, IgD, IgE, IgG, IgM in mammals) are defined by the structure of their heavy chains. Minor differences on heavy chains are found between subclasses of each class. Jackson ImmunoResearch offers polyclonal antibodies that are specific for mouse subclasses IgG1, IgG2a, IgG2b, IgG2c, and IgG3. We also have antibodies that are specific for camelid subclasses IgG 2+3. We currently do not have subclass-specific antibodies against other species.
Download Immunoglobulin Structure and Function Poster.

2. What are the differences between Fab, Fc, and F(ab')2 fragments?

These products are the result of proteolytic digestion of IgG. Digestion with papain results in Fab and Fc fragments, and digestion with pepsin yields F(ab’)2 fragments.

3. What is an antibody isotype?

Isotypes are distinct forms of antibody heavy and light chains, and may refer to class or subclass. Light chain isotypes are kappa and lambda, and heavy chain isotypes are alpha (IgA), delta (IgD), epsilon (IgE), gamma (IgG), mu (IgM). The heavy chains may be further differentiated as subclasses, e.g. gamma 1 (IgG1).

4. What is an isotype control?

Isotypes are distinct forms of antibody heavy and light chains, and may refer to class or subclass. Light chain isotypes are kappa and lambda, and heavy chain isotypes are alpha (IgA), delta (IgD), epsilon (IgE), gamma (IgG), mu (IgM). The heavy chains may be further differentiated as subclasses e.g. gamma 1 (IgG1).
An isotype control is a negative control that verifies specific binding of either a primary or secondary antibody. The isotype control is the same class or subclass as the experimental antibody, but is not specific for the antigenic target. Isotype controls may be purified IgG from normal serum of the species host of the experimental antibody; or in the case of monoclonal antibodies may be monoclonals of the same subclass, directed against an irrelevant antigen. Isotype controls for unlabeled antibodies are unlabeled, and controls for labeled antibodies are labeled with the same reporter molecule (fluorophore, enzyme, or biotin) as the experimental antibody.

Immunoglobulin Classes

Contact Us Introduction There are five classes of immunoglobulins, IgG, IgM, IgA, IgD, and IgE. These are distinguished by the Read More...

Lateral Flow Immunoassay: Methodology, Applications, and Considerations for Use

Contact Us Lateral flow immunoassay (LFIA) is a membrane-based technique for detecting specific analytes in complex samples. Advantages of LFIA Read More...

Western blotting guide: Part 6, Secondary Antibodies

Contact Us The secondary antibody detects the primary antibody, typically conjugated to a reporter molecule it enables the visualization of Read More...

Anti-Human IgE

Contact Us Introduction Jackson ImmunoResearch Mouse Monoclonal Anti-Human IgE antibodies are the latest addition to our suite of products suitable Read More...

Multiple labeling for simultaneous detection of several targets

Contact Us Multiple labeling is the process of sequential immunolabeling to detect multiple antigens by either immunofluorescent or colorimetric IHC/ICC. Read More...

Focus: Imaging with Nano Secondaries

Contact Us Combining the exquisite specificity our minimally cross-reactive antibodies have always offered with the unique penetrative capabilities of the Read More...

Disease surveillance for companion animals

Contact Us As we live our lives in close contact with companion animals, testing for infections that can pass between Read More...

JIR Journal Club. Review of Single B cell screening

Contact Us Single B cell screening rapidly identifies potent neutralizing antibodies for SARS-CoV-2 University of Michigan researchers used Jackson ImmunoResearch Read More...

Western blotting guide: Part 5, Primary Antibodies

Contact Us Primary antibodies are used to detect the protein of interest. Part 5 of the Western blotting guide details Read More...

Western blotting guide: Part 4, Membrane blocking

Contact Us Blocking is essential to prevent non-specific interactions between the transferred proteins, the membrane and the subsequent reagents used Read More...

Western blotting guide: Part 3, Electroblotting – Protein Transfer

Contact Us Electrophoresis allows the proteins separated by SDS-PAGE to be transferred from the gel onto a membrane by electrophoretic Read More...

Secondary Antibodies for Super Resolution Microscopy

Contact Us SRM with JIR Secondary Antibodies Super-resolution microscopy (SRM) encompasses any optical technique which circumvents the resolution limits of Read More...

Nano Secondary Antibodies

Contact Us Introduction Camelid species such as Alpaca and Llama produce a unique class of antibodies composed only of heavy Read More...

Western blotting guide: Part 2, Protein separation by SDS-PAGE

Contact Us Once prepared, the sample proteins are separated by PAGE (polyacrylamide gel electrophoresis), which may be performed under native Read More...

Western blotting guide: Part 1, Introduction and Sample Preparation

Contact Us In 1979, Towbin et al. first detailed the process of immunoblotting – the separation of proteins from a Read More...

Affinity Vs Avidity

Contact Us Affinity and avidity are terms used to describe the strength of the bond between an antibody and its Read More...


Contact Us Antibodies are such critical reagents for scientific research that a unique language has been coined relating to them. Here, we’ve Read More...

Serological testing for diagnostics and disease surveillance

Serological tests enable disease surveillance from initial infection through to the development of immunity against infectious diseases. The power of Read More...

Lateral flow tests for diagnostics

Lateral flow assays are one of the many types of immunoassays available for health monitoring. As point of care diagnostic Read More...

Selecting Fluorophores for Antibody-based Research

Fluorophores are essential tools for scientific research. They are widely used for immunoassay techniques such as flow cytometry, immunohistochemistry (IHC), Read More...