The National Institute of Standards and Technology (NIST), part of the Department of Commerce, is seeking vendors capable of providing quantitative analytical testing services for various analyte classes and matrix groups, including foods, supplements, and environmental solutions. This Sources Sought Notice (NIST-MML-25-SS01) aims to gather detailed information on vendors' testing capabilities, including methodologies, turnaround times, testing capacity, accreditations, and data reporting formats, as part of market research rather than a solicitation for proposals. The information collected will inform future procurement processes, with a Request for Quotation anticipated in early FY2025 and contract awards expected by mid-FY2025. Interested parties should respond with their organizational capabilities and experience to Don Graham at deg@NIST.GOV by the specified deadline.