Trace a sample through a LIMS or LIS, from request and accessioning to review, reporting and storage.
Why it matters
A busy lab handles thousands of samples a day. Each one must be matched to the right patient or batch, tested by the right method on a calibrated instrument, reviewed, reported to the right person and stored or discarded on time. Paper cannot keep up. Laboratory information systems do this work, and almost every lab job involves using one. Understanding how they track a sample makes you faster, and it helps you spot when something has gone wrong.
LIMS, LIS and ELN
| System | Typical setting | Centred on |
|---|---|---|
| LIMS (laboratory information management system) | Research, pharmaceutical QC, environmental, food, contract testing labs | Samples, batches, tests, specifications, instruments |
| LIS (laboratory information system) | Hospital and clinical labs | Patients, orders from clinicians, results reported to the medical record |
| ELN (electronic lab notebook) | Research and development | Experiments and the scientist's narrative |
The lines blur: many products combine features. The key difference is focus. A LIS lives inside the healthcare system and exchanges orders and results with the electronic health record, often using the HL7 messaging standard. A LIMS is built around samples, specifications and batch release.
The life of a sample
Whatever the system, a sample follows the same broad path.
- Order or request. A clinician orders tests (LIS), or a production step triggers QC testing (LIMS).
- Collection and labelling. The sample gets a unique ID, usually a barcode. Clinical labs require at least two patient identifiers (such as full name and date of birth) on the tube.
- Receipt and accessioning (login). The lab checks the sample against the request: right container, right volume, labelled correctly, received in time and at the right temperature. Samples that fail are rejected with a reason, and the requester is told.
- Chain of custody. Every handover is recorded. For forensic, drug testing and some environmental work, the chain of custody is a legal requirement.
- Test assignment and worklists. The system assigns tests and builds worklists or instrument run lists.
- Analysis. Instruments receive the run list and send results back through an instrument interface, avoiding retyping.
- Review and approval. QC must pass for the run. Results are checked against specifications or reference ranges. Many clinical labs use autoverification: rules that release normal results automatically and hold unusual ones for a person to review.
- Reporting. Results go to the clinician, the medical record, or a certificate of analysis for a batch. Critical values (results that suggest immediate danger to a patient) are phoned to a responsible person and the call is documented.
- Storage and disposal. The sample is kept for its retention period, then discarded, and the system records where it is and when it went.
What the system remembers
A LIMS or LIS keeps far more than results:
- Specifications and reference ranges, so out-of-range values are flagged.
- QC results for each run, linked to the patient or sample results they cover.
- Instrument status, including calibration and maintenance due dates. Many systems block a run on an instrument that is overdue.
- Reagent lots used in each run.
- Analyst training records, so only qualified people can enter or approve certain tests.
- An audit trail of every change.
Because all of this is linked, the lab can answer questions like "which results used reagent lot K2291?" or "which samples ran on HPLC-02 after its last good calibration?" in seconds. In the next lesson you will write those queries yourself in SQL.
Worked example: tracing a sample
A QC sample from tablet batch B-102 has ID S-2051.
- Logged in at 09:14 by AB; condition acceptable; stored at room temperature, shelf R3.
- Assigned: assay (HPLC) and dissolution.
- Assay run on HPLC-02, run R-778, system suitability passed, result 99.1 percent of label claim (specification 95.0 to 105.0).
- Reviewed by CD at 15:02; approved.
- Certificate of analysis generated for batch B-102 after all tests passed.
If an auditor asks how 99.1 percent was obtained, every link (sample, run, instrument, analyst, reviewer) is in the system.
Common mistakes
- Relabelling a tube by hand instead of reprinting through the system.
- Accepting a sample that does not match its request "to save time".
- Entering results by hand when an instrument interface exists, which introduces transcription errors.
- Sharing logins, which destroys attribution.
- Ignoring a system warning about an overdue calibration.
Quick recap
- LIMS focuses on samples and batches; LIS on patients and clinical orders; ELN on experiments.
- A sample moves through request, labelling, accessioning, testing, review, reporting and storage, with each step recorded.
- Specifications, QC, instruments, reagents, training and audit trails are linked, which makes tracing possible.
Try it
This lesson is quiz-only. Open the Do tab to check your understanding.