Isolation and characterization of six monoclonal antibodies raised against human RAD51 recombinant protein.

Monoclonal antibodies were produced against recombinant human RAD51 recombination protein. The antibodies of IgG subclasses were isolated from serum-free cell culture medium and purified by affinity chromatography on protein A-Sepharose. The antibodies can be used to detect specifically RAD51 protein on immunoblots of total cell lysates. Native RAD51 protein is specifically precipitated from lysates of human cells. In addition, these antibodies readily detect RAD51 in the cell nucleus by immunofluorescence staining. Epitope mapping on overlapping peptides spanning the complete primary amino acid sequence of human RAD51 revealed that three monoclonals recognize an epitope on RAD51 very close to the N-terminus of the protein (amino acids 16 to 20); the other three monoclonals interact with amino acids 85 to 95 of human RAD51.