An improved iliac lymph node method for production of monoclonal antibodies.

Monoclonal antibodies have been applied in a wide range of biological and medical studies since the advent of cell fusion technology. Although cell fusion techniques have been improved by using myelomas and reagents, researchers still find it difficult to produce monoclonal antibodies because of the long protocols, high costs, and low efficiency of obtaining hybridomas. To solve these problems, we first developed an iliac lymph node method in 1995 using rats. In this method, an antigen emulsion is injected intramuscularly into the tail base, and then B lymphocytes are isolated from the enlarged iliac lymph nodes. This method is approximately 10 times more productive than the conventional spleen method. Here, we present further improvements to the iliac lymph node method to render it easily applicable in both mice and rats. We found that the frequency of hybridomas secreting specific antibodies was over five times higher using the electro cell fusion method than using the polyethylene glycol (PEG) fusion method. This frequency using the iliac lymph node method with electro cell fusion is at least 50 times higher than that using the traditional spleen method, thereby leading to the reduction in the number of mice or rats to be sacrificed. In addition, only a single injection for immunization is necessary for the iliac lymph node method, opposed to three for the spleen method. Therefore, this method is rapid, inexpensive, and ethical for producing monoclonal antibodies.