Breath sampling and standardization

Success in breath biomarker discovery is driven by many factors, but sampling plays perhaps the most decisive role; inadequate sampling procedures can compromise breath samples, rendering them unreliable or unusable. The critical influence of sampling on data validity in breathborne biomarker applications has received widespread awareness and acceptance in the breath research community in recent years. Increasingly, efforts are being made in tailoring and standardizing sampling approaches to minimize variability and potential confounders. Aligned with these initiatives are considerations on standardized approaches for other aspects of breath research, including analytical platforms, representative patient/control cohorts, and data pre/postprocessing. This chapter explores aspects of sampling and issues that should be considered in procuring robust and reliable breath samples in both untargeted biomarker discovery and targeted biomarker validation. Further, the issue of standardization—and current lack thereof—in breath analysis is addressed, with a discussion on potential approaches to harmonize breath research pursuits.