Examples
Worked examples
- Is an instance
A 2024 audit of a 600-litre -80 degC freezer found over a third of boxes had no identifiable owner and were dispositioned with PI sign-off.
- Is an instance
An institution mandates that any sample untouched for seven years is flagged as unclaimed and scheduled for destruction unless the owning lab claims it.
Counter-examples
Looks similar, but isn't
- Not an instance
A clearly labelled, actively used cell line in continuous publication output is not an orphan sample.
- Not an instance
A regulatory biobank sample subject to a statutory retention period is not orphaned even if dormant.
Editorial commentary
An orphan or unclaimed freezer sample is a sample held in ultra-low-temperature (ULT, -80°C) or -20°C cold storage with no identifiable current owner, provenance record, or active research use — typically because the original researcher has left the institution, a project ended without a retention decision, or lab turnover broke the chain of custody. “Orphan” and “unclaimed” are the terms actually used in the sustainability-in-laboratory and cold-storage-management literature.
Why it matters
An orphan sample consumes freezer energy indefinitely while delivering zero research value: the freezer runs the same compressor cycle whether the box inside it is needed tomorrow or has sat untouched for a decade. Because ULT freezers are among a lab building’s larger single energy draws, a freezer full of unclaimed material is a direct, avoidable operating cost, not just a housekeeping problem.
How institutions find and resolve them
Periodic freezer audits — reviewing rack contents against a current sample-ownership database — are the standard detection method, often run alongside a broader lab waste audit. A written retention policy sets a default disposition: samples untouched for a defined period, commonly cited in the roughly 5-10 year range across institutional policies though this varies by sample type and any applicable regulatory retention requirement, are flagged for owner confirmation and, absent a claim, scheduled for consolidation or disposal. Getting this right requires PI sign-off and a documented decision trail, since destroying a sample that turns out to still matter is a research-integrity risk, not merely an efficiency one.
Where this sits in cold-storage practice
Identifying and clearing orphan samples is a recurring theme in the annual International Freezer Challenge, run jointly by My Green Lab and the International Institute for Sustainable Laboratories (I2SL), and in institutional cold-storage best-practice guidance generally — alongside setpoint review and preventive maintenance, covered under -80 freezer management.
References
- My Green Lab / I2SL International Freezer Challenge programme materials.
Also known as
Unknown Long-Abandoned Biological sample · Orphan sample · Unowned sample
Machine-readable encodings
Use in your systems
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