Each phage-displayed αF1 (CT1 through 8) or αLysozyme (CTD1.3) scFv was incubated with blocked live (A) or fixed (B) F1-positive Yersinia pestis (YP) A1122, Kim, India and India 195 or F1-negative YP Nairobi, Yersinia pseudotuberculosis 0104 (YPT 0104) and Yersinia enterocolytica 0107 (YE 0107). Phage-binding events were reported using αM13-HRP antibody. Background noise coming from buffers, secondary antibody or the cells was evaluated by including wells with no added phage (no phage). The value associated to each bar is an average of three experiments with corresponding standard deviation.