Recombinant Anti-CD38 x Anti-saporin Bispecific Antibody (Tandem scFv) is designed to be expressed as a scFv from an anti-CD38 antibody variable domains fused with a scFv from an anti-saporin 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 be used in pretargeting system and deliver immunotoxin to tumor cells. It is designed for the research of Multiple myeloma (MM); Hematologic malignancies therapy.