Standard Operating Procedure (SOP)

1. Purpose
The purpose of this SOP is to establish the procedure for the regular cleaning and maintenance of the Coulter Counter to ensure proper functioning, accuracy, and longevity of the equipment. Cleaning is essential for preventing contamination, ensuring sample integrity, and prolonging the lifespan of the instrument.

2. Scope
This SOP applies to the cleaning of all Coulter Counters used within [Company/Organization Name] for particle size analysis, cell counting, and other related functions. It includes external and internal cleaning processes to ensure proper sanitation and operational efficiency.

3. Responsibilities
Laboratory Manager/Supervisor:

Ensure that all personnel are trained in the cleaning procedure and that the Coulter Counter is cleaned regularly according to this SOP.

Laboratory Technicians/Operators:

Perform cleaning according to the procedure outlined in this SOP.

Record and report any abnormalities during the cleaning process.

Maintenance Personnel:

Assist with the cleaning of internal components, if needed, and ensure the Coulter Counter is properly maintained.

4. Definitions
Coulter Counter: A device used for counting and sizing particles suspended in a liquid based on electrical impedance.

PPE (Personal Protective Equipment): Protective gear, including gloves, goggles, and lab coats, worn to reduce exposure to hazardous materials.

Cleaning Solution: A suitable solvent or detergent for cleaning laboratory equipment without causing damage.

5. Procedure
5.1 Materials Required

1. Distilled Water
2. Manufacturer-recommended Cleaning Solution or mild detergent solution
3. Isopropyl Alcohol (IPA)
4. Lint-free Cloths or Wipes
5. Soft Brushes (if necessary)
6. Syringe or Pipette (for rinsing)
7. Disposable Gloves and Protective Eyewear

5.2 General Cleaning Guidelines.

1. Always wear disposable gloves and protective eyewear during the cleaning process.
2. Only use approved cleaning solutions or mild detergents to avoid damage to sensitive components.
3. Turn off and unplug the Coulter Counter before starting the cleaning process.

5.3 Cleaning External Components
Turn off the Equipment:

Ensure the Coulter Counter is powered off and disconnected from the power source before cleaning.

Clean the External Surfaces:

• Use a lint-free cloth dampened with distilled water to wipe down the external surfaces of the instrument.
• If necessary, use a mild detergent solution to clean off visible dirt or grime, and then wipe the surfaces dry with a clean cloth.
• Clean the Display and Control Panel:
• Use a soft, damp cloth to clean the display screen and control buttons.
• Ensure no water or cleaning solution enters the control panel to avoid damaging the electronics.

5.4 Cleaning Internal Components (Sample Chamber and Aperture)

1. Remove Sample Containers:
2. Safely remove any sample containers, probes, or attachments from the sample chamber.
3. Rinse the Sample Chamber:
4. Use a syringe or pipette filled with distilled water to flush out the sample chamber and aperture, removing any residual sample material.

Clean the Aperture:

Gently clean the aperture using a soft brush or lint-free cloth dampened with distilled water. Ensure no debris is left in the aperture.

Use Isopropyl Alcohol (IPA):

After rinsing, wipe the sample chamber and aperture with IPA to thoroughly clean and sanitize the area.

Dry the Internal Components:

Allow the cleaned internal components to dry completely or gently wipe them with a clean, dry cloth.

5.5 Cleaning the Fluidics System
Flush the Fluidics System:

Using a syringe or pipette, flush the fluidics system with a cleaning solution followed by distilled water to remove any debris or residual material.

Use IPA to Clean:

Flush the system with IPA to remove any water and cleaning solution residue.

Final Rinse with Distilled Water:

Perform a final rinse of the fluidics system with distilled water to ensure all traces of cleaning solutions and IPA are removed.

5.6 Cleaning of Electrodes (If Applicable)
Turn Off the Instrument:

Always power down the instrument before cleaning any internal components such as electrodes.

Remove Electrodes (If Applicable):

If the Coulter Counter design allows, carefully remove the electrodes for cleaning.

Clean the Electrodes:

Use a soft cloth dampened with distilled water or a mild detergent solution to gently clean the electrodes.

Rinse and Dry:

After cleaning, rinse the electrodes with distilled water and dry them carefully with a lint-free cloth.

5.7 Post-Cleaning Checks
Check for Moisture:

Ensure that all components, both external and internal, are completely dry before reassembling and powering on the equipment.

Reassemble the Instrument:

Carefully reassemble any parts or components removed during the cleaning process.

Perform a Test Run:

Turn the instrument back on and perform a test run or calibration to ensure it is functioning correctly.

6. Documentation and Record Keeping

• Maintain a cleaning log that includes:
• Date and time of cleaning
• Names of personnel performing the cleaning
• Cleaning solutions used
• Any issues encountered during the cleaning process
• Keep the log for a minimum of [insert duration, e.g., 1 year].

7. Compliance and Auditing
Ensure compliance with all relevant safety regulations and standards.

The laboratory supervisor will regularly audit the cleaning procedures to verify adherence to the SOP and identify areas for improvement.

8. References

1. Manufacturer’s User Manual for Coulter Counter
2. Laboratory Safety Guidelines

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