MicroPET imaging of bacterial infection of mice. Two-dimensional images of representative mice (ventral view) are depicted in the figure. MicroPET images were recorded over time from mice infected with either 64Cu labeled F. tularensis subsp. novicida, 64Cu labeled K. pneumoniae or 64Cu labeled E. coli. Mice were infected i.n, i.t, i.g, i.p, i.v and i.d with F. tularensis subsp. novicida (2 × 109 CFU/20 μl) and i.n with K. pneumoniae and E. coli using the same infection dose. Images were obtained at 0.25 hrs, 2 hrs and 20 hrs p.i. The red punctuated line represents the liver. The color scale on the right hand side of the figure is a linear scale that indicates percentage with red indicating 100% of signal and purple 0–10% or the lowest amount detected by imaging. Abbreviations: N: Nasal cavity, T: Trachea, L: Lung, GI: Gastrointestinal Tract, Li: Liver, S: Spleen, Le: Leg, Ce: Cecum.