We have three routes in developing human antibodies. The first and most straightforward method is to screen our human antibody libraries. The second method is to immunize premade “humanized” mice and then raise hybridoma cell lines

that produce human antibodies. The third method is antibody humanization. We rely on animals to produce non-human antibodies using either hybridoma or immune antibody library screening and screening methods; after that, the top candidate is humanized.

Through the flourish of antibody based therapeutic drugs, the demand of human or humanized antibody is synchronized growth. Due to the potential risk of immunogenicity, the full human antibody or at least humanized antibody (from xenogeneic sources) is required for further clinical application. Because of the serious ethical and moral issues, it is obviously an impossible task to directly immunize human beings with interested antigens. Nevertheless, several techniques have been developed as alternative solutions to overcome this limitation.