Heal Force shares some experiences on how laboratories should do a good job in the management of instruments related to clinical molecular testing. As an important component of the testing system, the performance status of the instrumentation plays a vital role in the accuracy and reliability of the results. Therefore, it is essential that laboratories manage their instrumentation well in order to ensure the quality of testing. However, some problems do exist in the management of laboratory instruments and equipment.

Clinical Molecular Testing instruments-Area Division

We should divide the laboratory in the first place. Generally, the laboratory can be divided into four zones. Zone 1 can be used for storage and preparation of reagents. Zone 2 can be used for specimen preparation. Zone 3 is used as an amplification zone. Zone 4 is used for product analysis. The instruments placed in each zone need label and have calibration information. We should put them at the right place.

ZoneFunctionEquipment and instruments
1Reagent storage and loading areaPipettes, centrifuges, vortex oscillators, refrigerators, thermometers, hygrometers, mobile UV lamps, etc.
2Specimen preparation areaBiological safety cabinets, nucleic acid extractors, pipettes, vortex shakers, centrifuges, constant temperature metal baths, refrigerators, thermometers, hygrometers, mobile UV lamps, etc.
3Amplification zoneNucleic acid amplifiers, thermometers, hygrometers, mobile UV lamps, etc.
4Product Analysis AreaNucleic acid hybridiser, refrigerator, pipette, thermometer, hygrometer, mobile UV lamp, etc.

The instruments and equipment in laboratory must be with high quality and good condition to meet the needs of all types of work so that the quality of testing could be convincing. This requires us to improve the accuracy and performance of our instruments. We need to pay attention to how the instruments are used, such a safety matters, to prolong their service life by proper maintenance. To do this, professional operators and managers need to be appointed. Operators should follow SOP for the operation and maintenance of the instruments. For example checking that the calibration is within the validity period before use and carrying out regular maintenance. Notify the instruments’ manager in the event of a malfunction. (The SOP document contains information on instrument name, performance, operation procedures, maintenance, calibration, etc.)

Management of the Use of Instruments and Equipment

Archives and Labels of Equipment and Instruments

In order to facilitate the management of equipment, we need to create an archive and label for the different pieces of equipment. The equipment archive records the basic information about the equipment. For example, basic information about the manufacturer, basic product information, product manuals, and maintenance and repair records of the equipment. The labels are mainly status labels and calibration labels. Usually the green status label indicates that the equipment is ready for normal use, yellow indicates a fault and red means that the equipment is out of use or obsolete; the calibration label indicates the date when the equipment was calibrated.

Equipment use, monitoring and maintenance records

For critical instruments and equipment, a form should be created to record their daily use, monitoring and maintenance practices. The forms should contain the instrument name, number, location, date of use/maintenance and instrument status. Instead of cumbersome manual records, we can set up an electronic testing system. Take a temperature and humidity monitoring system as an example. The temperature and humidity monitoring system is a real-time monitoring system based on wireless transmission, high precision and low power consumption, which allows for automated, intelligent and electronic recording and monitoring of temperature and humidity changes. The equipment needs to be maintained regularly according to the frequency of use and maintenance records need to be completed. Let’s take pipettes and bio-safety cabinets as an example.

  • The maintenance of pipettes is divided into external cleaning, internal cleaning and Sterilization.

External cleaning: A damp cloth with soap, detergent or 60% isopropyl alcohol is used to remove dirt from the outside of the pipette, which is then rinsed with double-distilled water and dried.

Internal cleaning: Removing the lower part of the pipette which can be cleaned using the external cleaning method.

Sterilization: UV sterilization is important. Steam sterilization could be useful when it is necessary (121 °C  for 20 min)

Daily maintenance:

1. Wipe the table surface with 75% alcohol after each use (do not use fluoride disinfectant)

2. Clean the surface of the UV lamp and the power outlet

3. Turn on UV disinfection for 30 minutes or more

Monthly maintenance.

1. Wipe the external surfaces with a damp cloth, especially the front and upper part of the cabinet, to remove any dust build-up

2. Check the proper use of all maintenance accessories

Annual maintenance:

1. Performance certification of the cabinet by a qualified and certified technician

2. Replacement of the UV lamp

3. Inspection of the safety cabinet’s high efficiency air filter

Measures in case of equipment failure

  • The equipment should be immediately and clearly marked
  • Repaired equipment that affects the performance of the instrument must be calibrated or monitored to confirm that its performance meets the requirements for use before use, specifically.

① Calibration of calibrate items

② QC monitoring results are within the permitted range

③ Monitoring results are compared with those of other instruments

④ Use of retained samples for discriminating the results of re-testing (refer to ③)

  • Check the impact on previous monitoring due to the above deficiencies and document the relevant analysis and treatment comments.

Instrument calibration

Definition:Under specified conditions, it is demonstrated that the measured, recorded or system displayed value of the instrument or meter is within acceptable limits by comparison with a standard, and that the calibration range should be within the appropriate measurement range.

A  Classification of instrument calibration

  • External calibration: is the calibration carried out by external organizations with calibration qualifications, including national authorities and instrument manufacturers’ lamps.
  • Internal calibration: is the calibration activities carried out by internal personnel of the unit, usually by qualified calibration personnel of the laboratory.

B   Instrument calibration requirements

Calibration should be carried out in accordance with the requirements of the national metrology department or the manufacturer, usually at least once a year. A formal calibration report should be issued. All types of instruments should be maintained by dedicated person.

The calibration plan should contain the calibration instrument, calibration unit, calibration period, calibration parameters, and criteria for determining that the calibration meets the requirements. Instruments to be calibrated typically include amplifiers, sequencers, hybridizers, bio-safety cabinets, high-speed frozen centrifuges, thermostatic metal baths, pipettes, thermometers, etc. Only trained and authorized person can perform calibration of instruments. Relevant training includes:

  • National or international metrology related rules and regulations, professional knowledge and skills training
  • Training provided by the instrument supplier
  • In-house training on standard protocols

Cases:

  • Calibration of temperature control systems
 Clinical Molecular Testing
Calibration of temperature control systems
Calibration cycleOne year
Calibration agencyMetrology institute/comparison
Calibration parametersTemperature, humidity
Judgement criteriaRelevant criteria
  • Calibration of spiking systems
 Clinical Molecular Testing
Calibration of spiking systems
Calibration cycleOne Year
Calibration agencyMetrology Institutes/Qualified Manufacturers
Calibration parametersPermissible error, repeatability of measurement
Judgement criteriaJJG646-2006
  •  Calibration of the detection system
 Clinical Molecular Testing
 Calibration of the detection system
Calibration cycleOne year
Calibration agencyMetrology Institutes/Qualified Manufacturers
Calibration parametersPermissible error, repeatability of measurement
Judgement criteriaJJG646-2006

C  Instruments should be clearly marked with their calibration status

If the instrument is calibrated and qualified, a calibration label should be affixed, containing the date of this calibration, the next calibration date, the calibration agency, etc. If the instrument fails, and did not calibrate on the specified date or requires maintenance and cannot be used, a red label should be affixed by the staff to indicate that the instrument cannot be used.

D  Other considerations

  • Does newly purchase equipment need to be calibrated before use?
  • When calibration gives a set of calibration factors, it should be updated in time.
  • Internal calibration should be in accordance with CNAS-CL31 “Internal Calibration Requirements”.
  • Information on internal calibration comparison records should include: comparison equipment number, calibration information used for the comparison equipment (calibration date, calibration validity, calibration unit), comparison time, standard equipment, actual measurement data, actual measurement data of the comparison equipment, judgement criteria, conclusion, comparison person, date of comparison, and the person in charge of the section.

Equipment Obsolescence

  • An end-of-life application should be completed and evaluated
  • Decontamination treatment
  • Confidential information removal

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