Abstract: Objective To prepare natural anti-keratin IgM monoclonal antibody. Methods Spleen cells of BALB/c mice raised in specific pathogen free conditions were directly fused with Sp2/0 myeloma cells. The hybridoma supernatants were tested by ELISA using pre-extracted keratin. The natural IgM obtained was further identified by immunochemistry and immunoblot methods. Results The cell fusion rate was about 60% without pre-immunization. About 14% supernatants reacted with the keratin antigen. Three hybridoma strains secreting natural IgM monoclonal antibody against keratin were obtained. The immunochemistry results showed that the natural anti-keratin IgM was able to bind to epidermis, sebaceous gland, hair follicule, and muscle tissues. Conclusion B lymphocytes in normal BALB/c mice spleen can produce natural antibody against kerain.

Key words: Antibodies, monoclonal, Immunoglobulin M, Hybridomas, Keratin