Quantification of post-PCR ITS DNA is linear in the range of oropharyngeal, lung, and contamination control samples. (A) Two serial dilutions of a standard sample of S. cerevisiae showed a linear response between input and post-PCR PicoGreen-quantification in the range yielding 0 to 60 ng/μL of ITS product. (B) Serial dilutions of two oropharyngeal wash samples from lung transplant recipients also showed a linear response in this range. (C) Genomic DNA from S. cerevisiae spiked into an oropharyngeal wash sample resulted in a linear increase in total DNA concentration within the 0 to 60 ng/μL range, as measured by post-PCR PicoGreen quantification. (D) Although the total concentration of post-PCR ITS DNA differed between sample types, the median concentration of contamination control samples was about 10% of the concentration in oropharyngeal wash. The median concentration of lung samples was only a few times that of contamination controls.