More and more biotechnological drugs especially antibody drugs enter into global marker, with the social benefits and success in business, which contributed to the global competition of biological innovation drugs and bio-similar drugs research and development. This competition drives a higher requirement for the production and stability of the expression host [Chinese hamster ovary (CHO) cell]. In addition to the optimization of downstream large-scale cultivation of production process, how to quickly obtain the stable expressed CHO cell lines in upstream screening, improve the ability of cell lines efficient expression, and increase the long-term stability of the cell lines and survival rate under the condition of the high density cultivation, is the goal of the world''s biological pharmaceutical industry.

 

Antibody (Ab), also known as immunoglobulin (Ig), is a large Y-shaped protein, produced by the B cells of the immune system, is used to neutralize pathogens, and is the body''s defense system [1]. The antibody is composed of Fab and Fc. In the organism, Fab targets to antigen specific binding, and Fc can combine to effectors [1]. With the continuous efforts of scientists, the structure and function of antibodies is well known now. The figure below shows the IgG1 structure.

 

(From Chiu ML, Gilliland GL. [2])

 

Because of its unique specificity and safety, antibodies play an important role in scientific research and human health. In scientific research, the antibody has the following purposes: observations protein localization in cells and tissues by immunohistochemistry, immunocytochemistry, immunofluorescence; separation of cells by flow cytometry instrument; research of the interaction between proteins by immune coprecipitation; qualitative and semi-quantitative o protein by western blot on; quantitative o protein by ELISA and ELISPOT, and so on. The application of antibodies in medicine includes medical diagnosis, disease treatment and prenatal treatment [3].Clinically, the disease can be diagnosed by detecting the expression of antibodies or antigens. Changes in IgA, IgM and IgG often indicate different types of liver damage [4].The diagnostic strategies used to detect antigens in patients include ELISA, immunofluorescence, Western blot, immunodiffusion, immunoelectrophoresis, and magnetic immunoassay. Cancer can be diagnosed by antibody and positron emission tomography (PET) labeled with 18F [5, 6]. So far, antibodies have been used to treat various diseases, such as rheumatoid arthritis, multiple sclerosis, psoriasis, and cancer. Since the first therapeutic mAb was introduced in 1986, more than 294 mAbs have been approved or used in clinical trials [7].

 

Antibodies are divided into polyclonal antibodies and monoclonal antibodies.

 

Polyclonal antibodies can be obtained by immune mammals (mice, rats, rabbits, goats, sheep, horses, etc.) or chickens, purified from serum or egg yolk. Monoclonal antibodies can be obtained through hybridoma technology.From monoclonal hybridoma cells, the sequence of amplification of antibodies can be used to produce recombinant antibodies. Compared with monoclonal antibodies derived from polyclonal antibodies and hybridoma, the recombinant antibody has the following advantages:  1) the antibody recognizes single epitope and has repeatability and specificity; 2) the influence of the instability of the hybrid tumor on the expression of the antibody was solved. 3) It can be modified on the sequence of antibodies to meet various needs; 4) mass production; 5) it is easier to control the differences between batches.
 

Antagen (Beijing) will provide flexible and quality services for customers, and meet the requirements of pharmaceutical supervision of global biopharmaceutical enterprises.