Currently our biodefense group focuses on utilizing phage display technology to create recombinant single-chain variable antibody fragments (scFvs) to vaccinia virus, E.coli 0157:H7, Vibrio vulnificus, Salmonella typhimurium, and Listeria monocytogenes.  The goal of our group is to utilize these antibodies and those developed to other pathogens for use in a real time/near real time fiber optic biosensor with our collabrative biodefense lab at the University of South Florida. 

                                                                                                                         Zhao et al. PNAS  October 19, 2004  vol. 101  no. 42  15029 CHEMISTRY

Phage display is a technique that allows researchers to create specific antibody fragments or peptides to a variety of homegeneous, heterogenous, and toxic antigens as an alternative to classic hybridoma technology. Typical phage libraries are compromised of a 100 million different peptide or scFv fragments (a single polypeptide compromised of human V_H and V_L domains attached to one another with a flexible glycine-serine linker) cloned into an ampicillin resistant phage vector in-frame with the phage's gIII gene separated by an amber stop codon and transformed into E.coli TG1 cells.   Antibody fragments or small peptides fused to the end of filamentous phage M13 are able to bind to antigens in a selection process called panning.   This essentially manipulates the monoclonal binding properties of an antibody using recombinant phage, and are therefore useable in ELISAs, Western Blots, immunoflurescence, etc.  Isolated phage whose DNA encodes the genes for a specific scFv or peptide can be isolated in a fraction of the time required for hybridoma monoclonal technology and with out animal immunization since phage propagation and thus antibody production is performed in vivo in bacteria.  Soluble scFv fragments are generated by infecting a non-amber stop codon supressor strain of E.coli which removes the scFv-pIII fusion.  ScFv genes can then be sequenced and sub-cloned into protein tagging expression vectors, such as green-flurescence protein (GFP) or Avitag^TM in vivo biotinylation casettes.  This is the power of phage display.