Patent ID: 8003383

Claim:
An isolated or purified vector suitable for efficient selection and affinity maturation of a recombinant antibody, the recombinant antibody having a leader peptide and being encoded by a recombinant antibody coding sequence, wherein the vector comprises at least one element able to reduce the expression level of said recombinant antibody, the at least one element being selected from a) a suppressed stop codon inside either the leader peptide or the recombinant antibody coding sequence; b) a low-efficient promoter driving transcription of said recombinant antibody coding sequence; or c) an inhibitor of the promoter driving transcription of said recombinant antibody coding sequence; and wherein the vector comprises a further element able to provide an efficient display of said recombinant antibody, the further element comprising: a) a sequence coding for a carboxy-terminal part of a minor coat protein pill fused to the recombinant antibody coding sequence; b) a leader peptide of the alkaline phosphatase of E. coli comprised as the leader peptide of the recombinant antibody; and c) a coding sequence for the minor coat protein pill fused to the recombinant antibody coding sequence with no amber codon therebetween.