Pipette fleet management: inventory, status and due dates

A list of pipettes is not enough to manage a fleet. The laboratory owner needs to know which pipette may be used, for what activity, by whom and up to which scheduled check. They must also reconstruct events when a shared device is overdue, unidentifiable or outside acceptance criteria.

The aim is to connect identity, intended use, status and history. The register may be paper-based or electronic, provided it is controlled and usable at the bench. Calibration methodology and uncertainty calculation require a separate metrological discussion.

Establish a stable identity for every pipette

Assign a unique, durable ID linked to serial number, model and configuration. Do not rely solely on button colour or position on a stand: similar instruments can have different histories and uses. If a label becomes illegible, reconcile identity using reliable evidence before restoring availability.

Organise the register into four blocks: identity (ID, serial number, model, principle, volume range and channels); use (permitted activities, tips, location, owner and assignment); control (status, applicable programme, latest activities, next due dates and restrictions); history (reports, anomalies, changes and decisions). For electronic models, also link the relevant configuration without confusing the equipment ID with a programme name.

A multichannel pipette remains one identified asset, but results must make the channels checked identifiable. See multichannel pipettes and channel consistency for this topic.

Define intended use and assignment rules

“Available” must mean available for a defined use. Link the required operating range, matrices, conditions, cleanliness requirements and permitted consumable combinations. Recent calibration does not automatically make a pipette suitable for every liquid or volume; tip compatibility remains part of the selection.

For dedicated instruments, clarify whether dedication concerns a person, method, matrix or area. For shared equipment, specify who checks status before collection, records use and returns it to the assigned location. Transfer between laboratories must update location and responsibility and assess contamination, transport and new operating conditions. A booking alone does not authorise use.

Translate status into permitted actions

Use a small set of unambiguous states, visible both in the register and at collection. Colours and icons help but should accompany text and an operational meaning. If the label and register disagree, suspend use and resolve the conflict. EU GMP Chapter 3 addresses measuring-equipment checks and identification or removal of defective equipment; the following matrix is an original organisational proposal.

Completion of a repair does not automatically change status to “available”. The transition requires the specified review. Any restrictions must be understandable to the user and technically justified, rather than held only in the owner's memory.

Manage due dates through a controlled programme

Distinguish calibration, intermediate verification and maintenance due dates: these are not interchangeable events. For each activity, identify the procedure, criterion, reference date, owner, advance warning and handling of delays. Also define what the deadline means, avoiding conflicting interpretations between labels and systems.

ILAC-G24:2022 / OIML D 10:2022 supports selection and review of recalibration intervals; it is guidance, not a mandatory GMP interval.

Justify the programme against use, criticality, applicable instructions and performance history. Schedule alerts early enough to arrange a replacement. If an activity is overdue, apply the defined procedure: no silent extension because of workload. Changing an interval needs a traceable rationale and approval; do not retrospectively rewrite the due date to make a delay disappear.

Link all events to the same asset

Calibrations, verifications, maintenance, adjustments and anomalies must be readable in one chronology while retaining their distinct meanings. A report must identify the pipette actually handled and its relevant configuration. Preserve results before and after intervention where available, applied criteria, restrictions and the laboratory's decision.

EU GMP Chapter 4 provides the reference for contemporaneous records and equipment history. Operationally, every status change should have an author, date, reason and linked evidence. For checks after an intervention, see pipette cleaning and maintenance.

A spreadsheet or commercial software package is not validated by definition. According to use and risk, define access, change control, formula protection, functional checks, retention and recovery. Sending a notification does not prove that a check occurred; a completed date field does not replace the result.

Reconstruct use without inventing a history

If a pipette cannot be identified or fails a check, block use, preserve evidence and start the relevant assessment. Seek preparation records, notebooks, assignments and other contemporaneous data linking the instrument to activities. The latest conforming check helps the analysis but does not by itself establish when deterioration began.

Simulated case. A shared pipette remains on the available-equipment rack, but its intermediate check is overdue. It is blocked and replaced with a suitable, already released instrument. Preparation records identify some uses after the due date; for others, the ID was not required and cannot be established with certainty. The owner documents this gap, separately collects dated recollections and evaluates the scope of potentially affected results with Quality.

No backdated records are created, and activities are not declared “unaffected” simply because a link is missing. A new check may contribute to the assessment, but it does not automatically certify the validity of every previous use. The case is illustrative and contains no actual laboratory data.

Maintain continuity and control retirement

Plan replacement instruments for critical volume ranges and applications; “same maximum volume” does not mean equivalent. Before lending, check compatibility, status, cleanliness, instructions and operator familiarity. At retirement, retain the ID and history, prevent accidental return and manage residues and destination under applicable procedures.

Review a few useful indicators: checks completed by their due date divided by total checks due, days unavailable, recurring failures and anomalies with untraceable uses. State the period and denominator; compare trends, rather than merely counting “green” pipettes. The aim is to prevent interruption and reduce evidence gaps. Other operational resources are in Liquid handling and sample preparation.

Sources and scope

EU GMP: Chapter 3, revision effective in 2015, §§3.41 and 3.44; Chapter 4, 2011, §§4.8–4.9 and 4.29–4.31. ILAC-G24 / OIML D 10, 2022 edition: recalibration-interval guidance. Official sources checked on 30 September 2026. The proposed register and matrix require adaptation to the local quality system.