Reactions of MAbs shown by Western blots following SDS-PAGE. Bacterial lysates from F. tularensis LVS, F. novicida U112, and F. philomiragia 029 (lanes 1 to 3, respectively) were reacted with MAbs M11D3, M13B10, M14B11, S11E7, and U22F2 and normal mouse serum (negative control). The reaction of MAb M14B11 against purified LPS from F. tularensis Schu (lane 4) is also shown. The positions of the molecular size markers are indicated (in kilodaltons).