A global threshold for PicoGreen-corrected OTU abundance identifies genera in experimental samples that are extremely unlikely to arise from contamination sources. (A) Histogram of PicoGreen-corrected OTU abundances in control samples. The inset plot shows abundances above the 95% limit of the distribution, colored by contamination sample type. (B) Agreement between the PicoGreen-corrected abundance of fungi computed from ITS sequencing and clinical culture results in BAL samples. (C) ROC curve of post-PCR ITS abundance vs. culture results for all cultured fungi. The sequencing method is a good predictor of culture results (AUC = 0.93).