The detection of C. burnetii load in BALB/c mice post-infection. Coxiella burnetii load in mice organs experimentally infected and tested by real-time quantitative PCR on 0, 7, 14, 21 and 28 days pi. In quantitative PCR analysis, the copy number per mouse was obtained with 1% of the DNA sample extracted from 10 mg spleen tissue. Coxiella DNA copies were determined in groups of eight mouse samples by quantitative PCR. The results are expressed as the average copy number of eight samples on a lg scale and error bars indicate the standard deviation.