Binding of recombinant scFv phages to FHA and the HBD-containing fragment of FHA in ELISA. The proteins used were maltose binding fusion proteins of FHA HBD, FHA RGD fragment (RGD), FHA CRD, or FHA type I domain (Mal85). FHA is the intact native FHA. The results shown are means ± SD of triplicate wells. T1, recombinant phage T1; T5, recombinant phage T5; T7, recombinant phage T7; 3H, parent phage.