Single-chain antibody fragments specific to the hepatitis B surface antigen, produced in recombinant tobacco cell cultures.

An anti-hepatitis B surface antigen (HBsAg), single-chain Fv antibody fragment (scFv) with a 6-histidine N-terminal tag was produced in cultured transgenic tobacco cells. Western blot and antigen-specific chromatography showed high levels of biologically active scFv in the culture supernatant (1 mg l−1) and in cells (5 mg kg−1). A simple one-step scFv purification was developed using immobilized metal ion affinity chromatography.