Which statement best defines Chain of Custody?

• A. Documentation that tracks sample custody and maintains sample integrity
• B. A method for labeling
• C. A disposal policy
• D. A calibration procedure

Answer: (A)

Chain of Custody is the documented record that shows who handled a sample, when they handled it, and under what conditions, from the moment of collection through to analysis, transport, storage, and final disposition. This trail helps ensure the sample’s integrity by preventing tampering, mix-ups, or contamination and by proving that the data associated with the sample are defensible and traceable. In practice, it includes details like collection time and place, the persons who took custody, transfer dates and conditions, transport temperature and containers, any aliquots or subsamples, storage conditions, and signatures on custody forms.

Choosing this option is best because it emphasizes the continuous, verifiable record of custody and conditions that protect the sample’s integrity throughout the surveillance process. The other options describe labeling, disposal policy, or calibration procedures, which address separate aspects of sampling and analysis but do not capture the essential, verifiable trail of custody.