Recombinant Anti-B cell lymphoma BCL1 Idiotype x Anti-CD3 Bispecific Antibody (Miniantibody) is a fusion protein of two scFv fragments combined with distinct specificity. One scFv of an anti-B cell lymphoma BCL1 Idiotype antibody variable domain is linked to another scFv of an anti-CD3 antibody variable domain by a flexible hinge region. This BsAb format has the decreased size and better penetration than conventional IgGs in the clinical diagnostics and potentially therapy. This BsAb can block cell adhesion. It is designed for the research of B cell lymphoma therapy.