How do you reconcile duplicate or conflicting sample identifiers?

Short answer

Quarantine conflicting identifiers, trace physical and digital evidence to the earliest reliable source, resolve under authorised procedure and preserve aliases and corrections. Never merge solely because samples look similar.

Why

Two containers arrive with the same accession barcode, or an instrument exports two results under slightly different labels. First pause the affected workflow and prevent unreviewed release. Gather intake documents, scanner history, rack position, collection time, parent-child aliquot links and instrument worklists.

Determine whether the records represent duplicate entry, relabelling, pooling or genuinely distinct specimens. Resolve only when objective provenance supports a defensible identity. Apply uniqueness constraints for identifiers that must be unique and record aliases explicitly for systems that legitimately use different IDs.

Corrections should not overwrite original identifiers or erase chain-of-custody evidence. If identity cannot be established, follow the lab policy for invalidation, recollection or escalation. Afterwards investigate why the conflict was allowed and test safeguards against recurrence.

Common mistakes

Deduplicating on name or collection date, which can collapse distinct specimens into one record

The interviewer might ask next

What would you do if all timestamps agree but the physical rack layout contradicts the interface map?