Freund's Adjuvant


Freund’s Adjuvant is perhaps one of the most commonly used adjuvants in research today. It is used in animal research to trigger a humoral antibody inflammatory response for the production of high titer antibodies.

CFA versus IFA

There are two types of Freund’s adjuvant: complete and incomplete. Complete Freund’s Adjuvant, or CFA, is a water in oil emulsion, which also contains inactivated mycobacteria (Mycobacterium tuberculosis is most frequently used). Incomplete Freund’s Adjuvant, or IFA, is the same water in oil emulsion, but does not contain the mycobacteria pathogen.

Advantages of Using Freund's Adjuvant

Freund’s adjuvant is one of the most effective adjuvants currently available and is essential for antibody production protocols and research. The adjuvant stimulates antibody production through two different mechanisms: the depot effect, and nonspecific immune-potentiation of macrophages.

CFA may be a good adjuvant for certain types of antigens, including antigens that are:

  • difficult to obtain
  • of small molecular weight
  • weakly immunogenic
  • only available in very small quantities

Disadvantages of Using Freund's Adjuvant

However, there are several serious concerns about the use of CFA. The primary concern is that the adjuvant can cause severe pain at the injection site of the animal being used. It also has the potential to cause serious complications, such as abscesses, chronic granulomas, and ulcerating tissue necrosis. Subcutaneous injections of the emulsion can cause fistulous tracts. If injected intramuscularly, the emulsion can spread to distant muscles or organs in the animal. At a minimum, close observation of the injection site and other general health parameters is essential when using CFA.

Using Freund's Adjuvant

To mitigate some of the concerns of using CFA, its use is generally recommended as only being used for the initial injection. Incomplete Freund’s Adjuvant can be used for subsequent injections because the side effects tend to be less severe.

Please don't hesitate to contact our lab at our toll free number (888) 513-9525, or email us at with any questions about how Freund’s Adjuvant can be used for your project.