Bulle About polyclonal antibodies

During the immune reaction, antigen-processing cells activate quiescent B-cells into plasmocytes to secrete immunoglobulins directed against that antigen. Each plasmocyte produces immunoglobulins that are specific for one epitope of a given antigen. Polyclonal antibodies are composed of a mix of immunoglobulins secreted by multiple plasmocytes clones, and thus recognise multiple epitopes on one antigen.


Bulle Advantages and drawbacks of polyclonal


Ready-to-use serum

Multi-epitope specificity is useful in detection and capture applications (IP and ChIP )

Protocols are well-proven and relatively short (from 53 days)

Non-specific antibodies often leads to background detection

High cross-reactivity due to non-specific antibodies contain in the serum


Bulle Available hosts

Using to a specific protocol according to the host, the desired immunogen is injected at predefined time intervals. Of course, the protocol can be adjusted depending on the immunoreactivity of the host.

The immunogen triggers a reaction from the host immune system and the subsequent production of antibodies directed against the foreign molecule. Resulting antibodies are then released into the blood.

At the end of the protocol, the whole blood is collected (except llama for which about 500 ml are sampled). Serum, which contains a large quantity of proteins including antibodies, is separated from blood cells and clotting factors. Antiserum is ready-to-use for various applications.




Bulle Our offers

Standard Project

Pack Project


We help you to select the more relevant immunogen depending on several factors (applications, cross-reactivity…).

We are also able to design and produce your immunogen.

Learn more about immunogen design



The most common host used to produce polyclonal antibody is the New Zealand white rabbit, but another host can be selected according to your needs.

On request, pre-immune sera can be tested in order to choose the most suitable hosts.

All along the immunization protocol, you’ll receive the intermediates test bleeds to run tests in your specific condition.


All along the immunization protocol, we manage the monitoring of the immunoreactivity evolution by performing ELISA test.

The results will allow use to guide you in your decision, if the immunoreactivity is suitable or if the protocol needs to be extended.



Although crude serum may be used in several applications, some require highly pure and specific antibodies.

Specificity can be dramatically increased by isolating antibodies from other components.

Bulle Standard project




The immunogen selection is a critical step because the immunogen has to trigger the best immune response from the host. Depending on several parameters relative to the expected antibody, we can provide you with our expertise and bring you advice to determine the best strategy.

The immunogen can be a protein, a synthetic peptide with or without post-translational modification (PTM), microorganisms, cells, genes or haptens. You can provide us the immunogen, but we are also able to design and produce peptides, genes and recombinant proteins.

Learn more about immunogen design.



Every species has its own immunoreactivity towards an antigen. The frequency, quantity and volume of injections must then be carefully adapted. Our strong experience allowed us to optimize protocols for each species, thus maximizing the probability to generate high amounts of specific polyclonal antibodies.

You will receive a calendar, reminding you the main steps of the protocol (injections, bleeds and deliveries) and the intermediate test bleeds at the indicated dates, to run tests in your specific conditions.

At the end of the immunization protocol, our engineers are available to advice you. At the end of the protocol you can request the final immune serum or extend it and request additional injections and/or test bleeds.


Rabbit Mouse Rat Guinea pig Chicken Goat Sheep Llama
Hosts Rabbit Mouse Rat Guinea pig Chicken* Goat Sheep Llama



53 days

67 days

88 days

67 days

81 days

88 days

90 days

88 days

88 days

88 days

Tests Bleeds 5 - 15 mL 30 - 50 µL 200 - 300 µL 200 - 300 µL 1 - 2 mL 5 - 20 mL 5 - 20 mL 10 - 20 mL
Final Bleeds 70 - 100 mL 0,5 mL 2,5 - 3 mL 5 - 10 mL 5 - 10 mL 1 000 mL 1 000 mL 500 mL


* Chicken produce a unique class of immunoglobulins called IgY, these IgY are naturally packaged at high concentrations in egg yolks, and a single egg yolk from an immunized chicken contains approximately 300 mg of IgY. On request whole eggs or separated egg yolks can be collected and stored frozen at -20°C for later antibody extraction with minimal risk of loss or degradation.

Bulle All Inclusive® project advantages




Pre-immune sera are sampled on Day 0 (D0) and intermediate bleeds are collected for testing all along the protocol.

For each test bleed, we provide you with an intermediate report showing the titer of the sera and the evolution of each animal’s immunoreactivity.

You will receive the results and the sample to perform your own tests.

Thanks to these data and our engineer’s know-how, we are able to advice you to make the right decision : continue, adapt or stop the project.




The combination of high specificity and huge diversity of antigen-antibody interactions has made immunoglobulins one of the most used tools in biological research to investigate the role of either characterized or potent proteins involved in all the signaling pathways which compose an organism.

Sample preparations such as antisera is ready-to-use for some non-sensitive applications. However, as antibodies represent only 20% of plasma proteins, they often need to be purified prior use to avoid unexpected interactions between other plasma components and your target.

Antibody purification involves selective separation of antibodies from other plasma components. We carry out various methods to purify antibodies ranging from poorly to highly specific ones.


Mammal Polyclonal Antibody Purification

Chicken Polyclonal Antibody Purification

¤  All Inclusive® services include the IgG purification up to 5 mL of the final serum

  • On a protein A or G column for anti-protein IgG
  • On an immuno-purification column for anti-peptide IgG

¤  Upon request :

  • Larger volume of serum (from 10 ml to more than 1000 ml) can be purified
  • Antigen affinity purification of the serum can be performed in order to drastically increase its specificity.

¤  All Inclusive® services include the IgY purification of 3 egg yolks per chicken by selective precipitation followed by ion exchange chromatography

¤  Upon request :

  • Separated egg yolk can be store frozen for subsequent extraction.
    • A purification up to 10 ml of the final serum can also be performed.



Bulle Brochures

Custom anti-protein polyclonal antibodies

Custom anti-protein polyclonal antibodies

Discover our complete anti-protein polyclonal antibody development service.

Custom anti-peptide polyclonal antibodies

Custom anti-peptide polyclonal antibodies

Discover our complete anti-peptide polyclonal antibody development service.