Fab and scFv are two main building blocks to generate bispecific fragments. Most bispecific fragments contain at least one type of these two fragments. The bispecific fragments composed of both Fab and scFv include Bibody (Fab-scFv), Tribody, Fab-scFv-Fc, F(ab’)2-scFv2, etc.
Fab-scFv-Fc: A fab and a scFv are fused, separately, to the N-terminus of the heterodimerizing Fc chains. KIH technology is applied to force to form Fc heterodimerization. (Cat. FABVC)
F(ab’)2-scFv2: The C-terminus of CH Fab is fused to the N-terminus of a scFv, resulting in an F(ab’)2-hinge-scFv2 molecule. The F(ab’)2-scFv2 has four binding sites, two for each antigen. (Cat. BABFV)