Rabbit serum is a component of blood obtained from a rabbit that contains blood plasma without fibrinogen or other clotting factors. It is used for various processes in biological and chemical research, particularly in the areas of immunohistochemistry and immunocytochemistry. Blood plasma is a yellow liquid in which other blood cells, such as red blood cells, are suspended; the majority of total blood volume is made up of plasma. Fibrinogen is a factor in blood that is responsible for the clotting or coagulation of blood. Rabbit serum is procured by centrifuging the coagulated blood of a rabbit, thereby removing the cellular components such as the red blood cells and the clotting factors such as fibrinogen.
There are many different experiments used in the course of biological research that require rabbit serum or the serum of another animal. Serum is often used for blocking purposes in various laboratory experiments. In immunohistochemistry, antibodies are used to detect the presence and abundance of certain antigens in a given tissue sample. The use of a blocking serum such as rabbit serum is important because it prevents nonspecific binding and interaction between the antibodies and non-targeted antigens. The serum generally must come from the same animal from which one of the antibodies used in the experiment comes.
Serums such as rabbit serum are also a common component in media used to maintain cell culture. A cell culture medium is a nutrient-rich substance in which cells are allowed to grow and multiply. While fetal bovine serum, or FBS, is the most common serum component in cell media, other types, including rabbit serum, may be used effectively. Serum is used primarily in media used to grow animal cells because it contains growth factors and hormones that are necessary for cell growth. Other cells, such as microbial cells, do not necessarily need these growth factors and hormones to grow.
There are many different companies that prepare and provide rabbit serum for labs to use in their experiments. These companies need to ensure their serum samples meet high standards of purity and sterility. Even a small amount of bacteria or other contaminant could wipe out a valuable cell culture or ruin the results in an immunohistochemistry experiment. As such, there are many different sterilization processes that are used to ensure that rabbit serum and other types of serum remain free of contaminants. Very few labs actually prepare their own serum, as specialized companies are better and more efficient.