Antibody production

Any vertebrate can be used as a source of antibodies. However, the most used animals for antibody production are rabbits, goats and sheep for polyclonal antibodies, and mice for monoclonal antibodies. For example rabbits are easy to care for and produce a moderate amount of serum often with high antibody titers. Goats or sheep also produce high-quality antiserum in larger amounts.

Monoclonal antibodies are obtained from a mouse cell line. These antibodies are produced by fusing single antibody-forming cells to tumor cells grown in culture. The resulting cell is called a hybridoma. Each hybridoma produces relatively large quantities of identical antibody molecules. By allowing the hybridoma to multiply in culture, it is possible to produce a population of cells, each of which produces identical antibody molecules. Although it is attractive to have a permanent supply of antibody with constant specificity and affinity, these cell lines may contain an unstable chromosome complement and their immortality depends upon proper storage and maintenance. The advantages, disadvantages and production of monoclonal antibodies have been discussed in several book chapters and reviews [8,9].

Antibody engineering and production of recombinant antibodies is a very promising field both for research and application [10,11].

Basic synthetic ways for preparation of the hapten derivatives (hapten design) were explored primarily in steroids more than 30 years ago [12]. Hapten immunochemistry thus represents a consistent area for the development and preparation of conventional antibodies. As new impulses for progress are largely depleted, further experimental strategies have been sought outside the classical immunochemistry area. In the past decade, molecular biology has generated fundamental changes in antibody production.

The discovery of polymerase chain reaction (PCR) simplified the cloning of monoclonal antibody genes from mouse monoclonal cell lines. These functional recombinant antibody fragments could be expressed in bacteria for use [13]. To take advantage of recombinant technology, efficient, large-scale screening techniques must be used.

Immunization procedures and schedules vary depending on the laboratory [14]. Usually an initial series of injections is followed by booster injections some weeks later. Animals are generally bled 7-14 days after each booster injection to determine the characteristics of the serum. Serum is collected or pooled following numerous booster injections and (or) the animal may be exsanguinated.

For long-term storage, antibodies are best stored frozen either in solution or as a lyophilized powder. Antibodies can be kept in solution containing 0.1% sodium azide (to prevent growth of microorganisms) in a refrigerator for up to a year. Solutions can also go through freeze-thaw cycles several times without too much loss of activity. Although antibodies are relatively hardy proteins, the concentration should be kept above 1 mg/mL during storage, solutions should be frozen quickly in liquid nitrogen before placing in a standard freezer and for long-term storage antibodies are lyophilized and stored in containers sealed under dry nitrogen.

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