Chain of Custody (Laboratory)

Chain of custody in a testing laboratory refers to the documented tracking of a sample from the moment it arrives at the lab through storage, sub-sampling, testing, and eventual disposal or return. A proper chain of custody includes: unique sample identification, receipt condition documentation, storage conditions, who handled the sample and when, any sub-sampling performed, and final disposition. For supplement testing, chain of custody matters because a contaminated, mislabeled, or substituted sample produces worthless results regardless of how sophisticated the analytical method is. Labs that handle chain of custody well typically have LIMS (Laboratory Information Management Systems), tamper-evident sample storage, and documented retention policies.