Binding of complement regulator FHL-1 and factor H by different borrelial strains. Strains ZS7, MMS, ZQ1, FEM1-D15, and LW2 incubated in NHS-EDTA were extensively washed with PBSA-Tween 20, and bound proteins were eluted using 0.1 M glycine (pH 2.0). Both the last wash (w) and the eluate (e) fractions obtained from each strain were separated by 10% Tris-Tricine-SDS-PAGE under nonreduced conditions, transferred to nitrocellulose, and probed with rabbit antiserum (αSCR1-4) recognizing both FHL-1 and factor H.