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In the current study, we introduce a method to design intrinsically soluble single chain antibodies (scFvs) that can be easily produced in bacterial expression systems in a soluble form. Summarily, CDR loops are grafted on framework regions derived from intrinsically soluble subclass 3 (VH3 and VL3) human germline sequences. Framework-donor sequences should carry CDR loops of interest (in terms of canonical classes) and contain special residues in their hydrophobic cores. Recombinant variable fragments resultant from CDR grafting are subjected to 3D modeling, mutated (if necessary), and superposed to parental variable domains. Recombinant type 3 variable domains with the least RMSD (Root-Mean-Square Deviation) values are chosen to constitute scFv moieties. The scFv designed using this method was shown to be soluble when expressed in bacterial cells.An insoluble scFv becomes soluble if frameworks are replayed by intrinsically soluble alternatives.Bulky amino acids in special positions act as a bridge and form a more integrated hydrophobic core.Composition of surface amino acids in some special positions may influence scFv solubility.scFv containing frameworks derived from VH3 and VL3 subclasses exhibit a high degree of solubility.