This is a sources sought notice to gauge industry interest and capabilities for providing gold-standard pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis of micro- and nanoplastics (MNPs) in biological samples such as blood, urine, and tissue. The work would support the Advanced Research Projects Agency for Health (ARPA-H) Health Science Futures Office. No budget, performance location, or non-submission timelines are specified.