Minibody is composed of a pair of single-chain Fv fragments which are linked via CH3 domains, and Fvs with distinct specificity, which paired to the former part through heterodimerization process. To promote the heterodimerization efficiency, single-residue mutations can be introduced into each CH3 domains to achieve the “knobs and holes” approach. Far more than that, additional cysteine residues can also be introduced into CH3 domains to stabilize the bispecific minibody structure. https://www.creative-biolabs.com/bsab/minibody-generation-service.htm