Chain of Custody in Research Environments

Chain of custody (CoC) refers to the documented sequence of possession and transfer of a material from one person, location, or status to another. Each link in the chain is a transfer event, and the record of those events, taken together, accounts for where a material has been and who has had responsibility for it at each stage. In research environments, chain of custody documentation creates a verifiable history that supports reproducibility and data integrity. This overview is factual and educational; it does not constitute a legal or regulatory framework for any specific application.

Research results depend on knowing what material was used. If a sample or material passes through several hands or locations without a clear record of each transfer, it may become impossible to confirm that the material used in an experiment was the same material received, stored under defined conditions, and prepared according to the intended procedure. Chain of custody documentation closes this gap by recording each handover, so that any result can be traced back through an unbroken sequence of accountable steps.

The relationship between chain of custody and the broader concept of traceability is close. Traceability covers the material’s complete history, including its source, storage conditions, and analytical data; chain of custody specifically addresses who held the material at each stage and how transfers were recorded. For the broader treatment of traceability, see Laboratory Sample Traceability.

A chain of custody record captures key information at each transfer: the date and time, the identity of the material (name and batch number), the quantity transferred, the sender and recipient, the reason for the transfer, and any relevant condition observations. Where the material is moved between storage locations, the origin and destination locations are recorded. Where the material is transferred between individuals, both parties may sign or otherwise confirm the transfer.

Electronic systems can automate parts of this process by logging transfers as part of normal workflow, creating an automatic audit trail. Paper-based systems require manual entry at each transfer, which places the responsibility for completeness on the individuals involved. In either case, the record should be made at the time of the transfer rather than reconstructed later, since contemporaneous records are more reliable than those recorded from memory.

A physical label on the material is the primary means of maintaining identity through a chain of custody. If a material is transferred without carrying a label that identifies it, the chain of custody is broken at that point regardless of what the written record says, because there is no way to confirm that the material received is the same as the material described in the transfer record. Relabelling on transfer, if necessary, should be done immediately and recorded.

For dry research materials in sealed vials, the label on the vial carries the material name and batch number that form the basis of the chain of custody record. Maintaining the integrity of that label throughout transfers and storage is essential for an unbroken chain. For guidance on label requirements and durability, see Laboratory Sample Traceability.

The chain of custody for a research material begins at the point of receipt from the supplier. The receiving record establishes the starting point: who received the material, when, from whom, in what condition, and with what batch documentation. From that point, every subsequent transfer extends the chain. For the details of what a thorough receiving procedure involves, see Research Material Receiving Procedures, and for how documentation supports the chain across the material’s life in the laboratory, see Laboratory Documentation Best Practices. Our general approach to material consistency is described on the Quality page.