Figure 1: Cluster analysis (dendrogram) of sequencing results. This is a heat map of the species identified by pyrosequencing present in each atherosclerotic plaque sample analyzed and the number of copies for each species identified (relative quantification). This information is then mapped to identify how close the samples correlate to one another. It is interesting that for samples 15A and B, 16A and B, and 17A and B that the same species were found in each different location within the same plaque, and their relative prevalence remain the same from the A location to the B location. The only thing that differed was the absolute number of bacteria between the locations. For contamination it would be expected that the species would be random and their relative quantification within the different locations of the same sample would definitely be quite different. The heat map clearly shows that the dominant species in one location remains the dominant species in the second location, raising the possibility that the presence of the bacteria is not random contamination but rather propagation of bacteria in situ.