Figure 4: Affinity calculation of the LF8-Fab. Affinity was measured by noncompetitive ELISA. The concentration of the LF8-Fab and the absorbance at 405 nm were plotted to two hyperbolic curves using GraphPad Prism software. The LF8-Fab could identify LF in a dose-dependent manner with an affinity constant of 3.46 × 107 L/mol according to the calculation of SPSS statistical software.