Comprehensive method for producing high-affinity mouse monoclonal antibodies of various isotypes against (4-hydroxy-3-nitrophenyl)acetyl (NP) hapten

Monoclonal antibody (mAb) technology has significantly contributed to basic research and clinical settings for various purposes, including protective and therapeutic drugs. However, a rapid and convenient method to generate high-affinity antigen-specific mAbs has not yet been reported. Here, we developed a rapid, easy, and low-cost protocol for antigen-specific mAb production from single memory B cells. Using this method, high-affinity IgG1 mAbs specific to the hapten 4-hydroxy-3-nitrophenylacetyl (NP) were established from NP-CGG immunized C57BL/6 mice within 6 days. Our mAb production system allows flexible switching of IgG1 to any other isotype with the same paratope, enabling the absolute quantification of antigen-specific serum antibody titers and affinity maturation. Additionally, we established a protocol for the production of IgM and IgA, retaining their functional pentamer and dimer structures. This method is also effective against human antigens and pathogens, making it a powerful tool for mAb development in both research and clinical settings.