Recombinant Anti-CD38 x Anti-saporin Bispecific Antibody (scFv-CH1/CL) is designed to be expressed as two chains. One scFv from an anti-CD38 antibody variable domain is fused to CH1 and the other scFv from an anti-saporin antibody variable domain fused to CL, or vice versa. And the CH1 and CL domains are linked covalently via a natural disulfide bond. 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.