Fig. 6

Analytical specificity. a The stratification of samples with different contamination levels on the 450HM array. There are eight different, color-coded samples labeled A through H. Each initial sample is divided into six replicates, which are contaminated with six different levels of bacterial cells; for example, A1 = no bacterial contamination, A2 = 10% of cells in sample are bacterial in origin, A3 = 20% of cells, A4 = 30% of cells, A5 = 40% of cells, and A6 = 50% of cells. b The number of aberrantly methylated loci per sample for different concentrations of bacterial cells (E. coli DNA) in the sample. c Scatter plot of the measure of probe intensity vs. the number of aberrantly methylated loci (failed probes are removed before calling aberrant methylation) per sample, stratified by the amount of bacterial contamination in the sample