A single chain Fv antibody displayed on phage surface recognises conformational group-specific epitope of bluetongue virus.

A single chain fragment variable (scFv) antibody gene was isolated from hybridoma cell line secreting monoclonal antibody (MAb) 20E9 that recognises bluetongue virus (BTV) VP7. DNA fragments encoding variable regions of heavy and light chains were amplified by RT-PCR and library of scFv was constructed in phage vector. Two scFv clones that were selected showed specific reactivity with conformational epitope VP7. The N-terminal 22 amino acid residues of 20E9 light chain were identical to that deduced from scFv DNA sequence. An in-frame TAG stop codon was found in the coding sequence and its potential role in regulating the expression and stability of scFv in phage is discussed.