Recombinant Anti-BAFF x Anti-B7RP1 Bispecific Antibody (Tandem scFv) is designed to be expressed as a scFv from an anti-BAFF antibody variable domains fused with a scFv from an anti-B7RP1 antibody variable domains. It contains a His-tag at the C/N terminus for affinity purification. The BsAb exits as monomer in reducing and non-reducing conditions. This BsAb can bind and inactivate two ligands simultaneously. It can inhibit B cell survival and T cell costimulation. It is designed for the research of Systemic lupus erythematosus (SLE) therapy.