Somewhere in the walk-in fridge
A client asks for a retest on a sample from three weeks ago. Someone goes to the walk-in fridge, where samples are kept in crates by date of receipt, roughly. After twenty minutes of searching, the sample turns up in the wrong crate. Meanwhile, the freezers are full because nobody has had time to clear out samples past their retention period, and some clients have longer retention agreements that nobody wants to get wrong.
Why storage gets out of control
- Storage locations are recorded loosely, or not at all.
- Retention periods vary by client, contract and sample type.
- Disposal is done in occasional clear-outs, not routinely.
- Samples on legal hold or client request are marked with a sticky note.
- Nobody knows how full each storage unit is.
Retention requirements also differ by sample type within the same client. Some samples must be kept frozen, some refrigerated, some for longer because of the kind of testing done. A single rule such as 'keep everything for a month' is either too short for some or wastefully long for others.
What it costs
Time is lost searching for samples. Retests are delayed. Storage runs out, leading to extra equipment or ad hoc clear-outs. Disposing of a sample that a client asked to keep, or that should be held, causes serious problems. Keeping samples far past retention costs space and energy.
| Task | Loose records | Storage tracking |
|---|---|---|
| Store | Crate by date | Scanned to rack, box or shelf |
| Find | Search the fridge | Search by sample ID, go to location |
| Retention | General rule | Per client and sample type |
| Holds | Sticky note | Recorded hold that blocks disposal |
| Disposal | Occasional clear-out | Routine disposal list, checked and confirmed |
Disposal itself has a cost in time and in waste handling, and doing it in large, irregular batches makes it harder to plan. Routine, smaller disposal runs spread the work, keep the waste stream predictable and avoid the week when every freezer is full at once.
How we build it
- Storage units, shelves, racks and boxes get barcodes. After testing, samples are scanned into a location.
- Retention periods are set by client, contract and sample type, with holds recorded where a client or your procedures require.
- Searching for a sample shows its location. Moving it is a scan.
- A disposal list is produced on a schedule, listing samples past retention with no hold, grouped by location.
- Staff check and confirm disposal, and the record is updated in the LIMS where it allows.
- Capacity views show how full each unit is.
Disposal only happens after a person confirms it. Holds always block samples from the disposal list.
For labs that also run chain of custody work, disposal of those samples can require extra steps, such as a witness or a certificate. Those steps are added to the disposal list for the relevant samples so they are not missed in a routine clear-out.
What changes
Retests start sooner because samples are found straight from their recorded location. Disposal becomes a routine task rather than a crisis. Client-specific retention and holds are respected. Storage is used more evenly.
Retrievals for client queries become routine rather than a hunt, which shortens the time to a retest. Managers can also see how much storage is committed to each client, which is useful when agreeing longer retention terms or planning new equipment.
Recognise this?
- Finding retained samples takes a search.
- Storage is full of samples past retention.
- Client-specific retention is hard to follow.
- Holds are marked with sticky notes.
- Disposal happens in occasional big clear-outs.