Sample and Inventory Management
TL;DR
Chain of custody is the documented record of who held a sample, when, where it was kept and why it changed hands, from collection or receipt until it is used up or destroyed. With every handoff signed or logged with a timestamp, a lab can show that the material it analyzed is the material that arrived.
Chain of custody is the documented record of every person who handled a sample, when they had it, where it was kept, and why it moved, from the moment it was collected or received until it was used up or destroyed. It lets a lab show that the material it analyzed is the material that came in the door, and that nobody without authorization got to it in between.
The idea comes from forensics, where evidence that can't be accounted for at every step can be thrown out of court. The NIST definition still reads like an evidence-room rule: document each person who handled the item, the date and time of each transfer, and the purpose of the transfer. Environmental and toxicology testing labs took it over, and ISO/IEC 17025 covers it under clause 7.4 on the handling of test items. Research labs mostly meet it when samples leave the building or move between teams.
It often gets used interchangeably with sample tracking, and the two do overlap. Sample tracking tells you where a sample is and what has been done to it. Chain of custody is about accountability: who was responsible for the tube at each moment, and whether every handoff is backed by a signature or a timestamped entry. So a lab can track its samples well and still have a custody gap, for example a courier pickup that never got written down.
On paper, it's a form that travels with the samples, and whoever takes them over signs and dates the transfer. For a set of plasma samples going to a contract lab on dry ice, the sequence runs like this:
Inside one lab the scale shrinks and the logic stays the same. An analyst pulls aliquot 3 of a reference standard from box B4 in the -80°C freezer, and the record should say who took it and which run it went into.
Custody records rarely fail dramatically. A box gets moved to another freezer during a defrost with no note, or a rack changes hands in the corridor and the form is filled in from memory a week later.
And not every tube needs a signed transfer. Test articles in a GLP study, patient-derived specimens, anything shipped to or from a CRO, and anything that could end up in a regulatory submission usually do. A signed transfer for every bottle of buffer would bury the records that matter, so a short SOP covering receipt and shipment, plus a custody form or an electronic equivalent, is enough to start. In IGOR, Sample History in the Inventory module records every action on a sample with the user who took it and a timestamp.
Chain of custody is a regulatory requirement for studies conducted under GLP. In the United States, 21 CFR Part 58 requires procedures for handling test and control articles so that proper identification is maintained throughout distribution and the receipt and distribution of each batch is documented (21 CFR 58.107). Specimens have to be identified by test system, study, nature, and date of collection (21 CFR 58.130(c)), and archived specimens must be stored where only authorized personnel can enter (21 CFR 58.190). The OECD Principles of Good Laboratory Practice set equivalent expectations for GLP studies in OECD member countries.
So when a sponsor or an inspector asks how the specimens got from the animal facility to the bioanalytical lab, the answer has to be a document. Somebody remembering who carried the box doesn't count. If there is a gap, the lab can't show the samples were protected during that period, and the affected data may have to be excluded or the work repeated.
Outside GLP, chain of custody is good practice and not a legal obligation. It still pays off the first time a collaborator emails to ask whether the cell pellet they received is the one you meant to send.
A chain of custody form needs a unique sample ID, a description of the material and the number of containers, the collection or receipt date, and a signed, dated entry for every transfer between people or locations. Most forms also note the condition of the samples on receipt, such as whether the seal was intact or any dry ice was left. For shipments, add the courier and tracking number.
Not legally, for most academic and early discovery work. It is a regulatory requirement for studies conducted under GLP (21 CFR Part 58 in the United States, or the OECD GLP Principles elsewhere) and standard practice in forensic and accredited testing labs. Plenty of research labs keep custody records for shipped samples anyway, because sponsors and collaborators ask for them.
The lab can no longer show who had the sample for that period, so the identity or integrity of the sample can be challenged. In GLP or forensic work the affected results may be excluded, or the samples reanalyzed from a retained backup.
The gap goes into a deviation report with an assessment of the risk to the data, and the step in the procedure that allowed it gets fixed.
Yes, provided each transfer is attributed to a named user with a timestamp and the record is protected from undetected changes. For FDA-regulated work, 21 CFR Part 11 sets the requirements for those electronic records and signatures. In IGOR, Sample History records every action on an inventory sample with the user and a timestamp.
This page is a general overview for lab scientists. It is not formal compliance or legal advice, and requirements for a specific study depend on the regulations that apply to it and on your own SOPs and quality system.