Species For The Production Of Antibodies, Which Is Better?
July 3, 2020
The use of different species for the production of antibodies is more and more frequent, due to the methods of obtaining it and the various characteristics that the host selected for its production confers on the antibody .
Although the species that are commonly used for the production of monoclonal antibodies are mainly reduced to mice and rabbits (remember this post on the Advantages of rabbit monoclonal antibodies ) the range in the case of the production of polyclonal antibodies is more extensive.
In this entry we summarize the characteristics of the different species for the production of polyclonal antibodies that are used most frequently, and the advantages of each one.
Due to its widespread use and the existing optimization in immunization and screening protocols in this species, the rabbit is the host of choice for the production of polyclonal antibodies.
In general terms, about 20 mL of antiserum are usually obtained from the bleeding of a rabbit, containing on average between 1 and 5 mg of specific antibody against the target protein.
When should we do without the rabbit and opt for other species? Fundamentally in two cases:
When we need to produce large amounts of antibody and have to resort to a larger animal to optimize productivity.
When the target protein is highly conserved in mammals (and therefore does not awaken the immune response in rabbits) and we have to resort to species with a greater phylogenetic distance.
The rat is the species of choice when a second species is required in which to generate the antibody. In this case, as is the case with rabbits, as they are species of routine use, immunization and screening protocols are highly optimized.
In terms of productivity, a rat is usually obtained on the order of 3mL of antiserum after final bleeding.
The goat is the species of choice in those cases in which you want to obtain higher amounts of antibody , mainly for two reasons:
It is more cost-effective, since up to 8 times more antiserum can be obtained from bleeding than in a rabbit, and also in a higher concentration (up to 20mg / mL), reaching double or even triple that obtained in rabbits.
All the antibody generated will come from a single animal, unlike what would occur with rabbits, thus reducing variability and obtaining more homogeneous antibodies.
The characteristic chicken immunoglobulins (IgY) have several advantages over the IgG isotype antibodies that are usually obtained in mammals:
IgYs do not bind to the mammalian Fc receptor, which significantly reduces background noise, nor rheumatoid factors, which would avoid false positives in the autoimmune disease study cases.
On the other hand, chicken IgYs do not activate the complement pathway either.
To these two peculiar characteristics, we must add two additional advantages:
The high productivity (a single egg yolk can have 100 mg of total IgY, approximately what would be obtained with about 10 mL of rabbit antiserum).
The phylogenetic distance with other species, which allows a greater response in the case of highly conserved target proteins in mammals.
If you want to expand the information about chicken antibodies, we remind you of this previous entry about 5 reasons to use chicken antibodies .
Camels (camels, llamas and dromedaries), like chickens, produce a characteristic type of immunoglobulin called heavy chain IgG (hcIgG) , which differs structurally from conventional IgGs and has very interesting characteristics in the field of scientific research. .
In these hcIgGs, the antigen-binding domain can be made up of a region as small as a 15 kDa fragment, allowing these regions to access spaces that an IgG would not reach.
The immunization cycle to obtain antiserum in camelids is about two months, and its economic cost is significantly higher than the production of polyclonal antibodies in rabbit, rat or goat.
In summary, when selecting the species for the production of antibodies, it is essential to assess aspects such as the amount of antibody we want to produce, the phylogenetic distance with the target protein or the budget we have, among others.