SOP: Laboratory Sample Receiving and Logging
Every analysis begins at the receiving bench. A mislabeled sample or a broken cold chain here invalidates everything downstream, no matter how good the instruments are. Disciplined receiving is the lab’s first quality gate.
General laboratory procedures form the foundation every analytical result stands on. Balances, pipettes, glassware, and waste handling rarely make headlines, but errors here propagate silently into every test the lab performs. Treating these routines with the same rigor as the analyses themselves is what separates reliable laboratories from the rest.
Purpose
To receive, inspect, log, and store laboratory samples with full traceability from receipt to disposal.
Scope
Applies to all samples entering the food analysis laboratory: routine QC, complaints, and external client samples.
Equipment and Materials
- Sample logbook or LIMS
- Calibrated thermometer (infrared or probe)
- Refrigerators (0 to 4 C) and freezers (minus 20 C), monitored
- Labels and markers
- Chain-of-custody forms
Procedure
- Check the delivery against the submission form: sample IDs, number of units, and requested tests.
- Inspect packaging integrity. Note any damage, leakage, or thawing.
- Measure and record the receipt temperature: perishable samples must be at or below 4 C (frozen at or below minus 18 C).
- Assign the laboratory sample number and label every unit. Link it to the client sample ID in the log.
- Record: date and time of receipt, receiver initials, sample description, lot, tests requested, storage location, and any deviations.
- Store per the test requirements immediately: refrigerate, freeze, or hold at ambient in designated areas.
- Notify the requester of any nonconforming samples (warm, damaged, insufficient quantity) before analysis.
- Retain reserve portions per the retention policy; dispose of the rest after the retention period via approved routes.
Recording Results
The sample register is the record. Every entry needs a unique lab number, full traceability to the client ID, storage location, and disposition date. Audit the register monthly.
Quality Control
Document every activity in real time in bound logbooks or the validated electronic system; never backdate entries. Review logbooks weekly for completeness and sign off. Train all personnel on this procedure before independent work and reassess competence annually. Track calibration and maintenance due dates on a master schedule with alerts. Audit compliance with this SOP during internal audits and record findings with corrective actions. Retain all records per the document retention policy.
Troubleshooting
- Warm perishable samples: quarantine and notify; do not analyze micro samples above 8 C without QA approval.
- Illegible labels: relabel immediately against the submission form; never guess.
- Missing submission forms: hold the samples unlogged-area and chase the paperwork; unlogged samples must not enter testing.
- Missed calibration due dates: implement automated reminders 2 weeks ahead; tag equipment with visible due-date labels.
- Incomplete logbook entries: review logs at shift handover; the next user should be able to reconstruct the work.
Interferences and Limitations
These procedures control the laboratory environment, not the analysis itself; their value depends on consistent execution by trained personnel. Human error remains the largest source of variation: rushing, skipping verification steps, or working while fatigued undermines the entire quality system. Equipment drifts between calibrations, so the scheduled verification frequencies are minimums, not targets. Review and update this procedure whenever equipment changes or audits reveal gaps.
Safety Notes
- Assume unknown samples may be hazardous; wear gloves.
- Report suspicious packages per site security procedures.