Figure 2.

Timing of tick transmission of B. burgdorferi to mice. Mice exposed to infected ticks for various time periods (Fig. 1B) were tested for infection by Western blotting (A) or culture (B). Numbers on the left in A are molecular masses of markers in kDa. In a few cases (hr 37–38, 39–40, 55–56) all of the ticks were not recovered from the mice. These animals were not tested for infection because we could not accurately determine the length of tick exposure. IMS, infected mouse serum; NMS, normal (uninfected) mouse serum.