As the core equipment for aseptic operations, ultra clean workbenches are widely used in fields such as biopharmaceuticals, cell culture, and microbiological testing. Its performance depends on standardized operating procedures and meticulous daily maintenance. The following key details are explained from three aspects: preparation stage, operating standards, and maintenance points:
1、 Preparation and self check before startup
Environmental confirmation
Ensure that there are no dust generating operations in the work area (such as cleaning and drilling), with indoor temperature controlled at 18-26 ℃ and relative humidity ≤ 70%.
Check the stability of the power supply voltage. If the voltage fluctuation exceeds ± 10%, a regulated power supply should be equipped.
Tabletop pretreatment
Wipe the countertop and inner walls with 75% medical alcohol or specialized disinfectant, with a focus on cleaning the gaps in the return air grille.
Turn on the UV lamp for pre disinfection for 30 minutes, and turn off the fan during the irradiation period to avoid ozone overflow.
Attention: Ultraviolet radiation is harmful to the human body. When disinfecting, leave the work area and close the glass sliding door.
Fan system detection
Activate the efficient air supply system and observe the wind speed value on the LCD screen (conventional vertical flow ≥ 0.3m/s).
Feel the direction of the incoming airflow with your hands, and it should normally be in a uniform laminar state without obvious eddies.
2、 Standardized operating procedures
Personal protection requirements
Wear one-piece protective clothing, masks, hair covers, and nitrile gloves, and do not expose the area above the wrist.
Spray 75% alcohol on both hands before entering the workspace and rub until dry to avoid bare hands contact with experimental equipment.
Material access management
All vessels and reagents entering the work area must be disinfected with ultraviolet light through the transfer window for 30 minutes.
The items are arranged in a "Z" shape at the middle and rear of the table, with a 15cm buffer zone reserved at the front and back to ensure smooth airflow.
Do not place tall objects such as centrifuge tube racks and waste liquid tanks at the front end to block the airflow.
Operational Action Standards
Arm bending angle ≤ 60 °, elbow close to body to reduce disturbance, operating radius not exceeding shoulder width.
Immediately immerse the vaccination ring/gun head into a beaker containing 75% alcohol after use, and do not leave it suspended.
Flame sterilization uses a miniature alcohol spray lamp, with a heat source distance of ≥ 10cm from the tabletop to prevent burning damage to the HEPA filter.
Principles of emergency response
When the culture medium spills, immediately cover the contaminated area with sterile gauze and wipe it in a single direction until it is completely absorbed.
If live bacteria leak, UV disinfection should be extended to 60 minutes, and a sealed space should be fumigated with 0.5% peracetic acid.
3、 Daily maintenance and quality control
Filter efficiency monitoring
Quarterly detection of sedimentation colony count (exposed to a Φ 90mm culture dish for 30 minutes), meeting the standard of<1 CFU/dish.
When the fan noise increases abnormally or the wind speed is below 80% of the set value, immediately replace the pre filter.
Reminder: HEPA filters must be replaced after 800 hours of continuous use, and new and old filters must not be mixed.
Performance Verification Record
Monthly particle counting tests should be conducted, and the number of 0.5 μ m particles should be less than 3500 particles/m ³ (ISO Class 5 standard).
Save the annual third-party testing report, which includes parameters such as wind speed uniformity, illuminance intensity (≥ 300lx), and noise<65dB (A).
4、 Special precautions
List of Prohibited Items
Do not store volatile chemicals (such as formaldehyde, ethanol) in the workspace
Prohibit the use of tools such as chalk and pencils that are prone to generating dust when writing labels
If the filter element needs to be disassembled during maintenance, the power must be cut off first and a warning sign must be hung in a prominent place
By strictly implementing the above details, it is possible to ensure that the ultra clean workbench maintains a level 100 clean environment, effectively guaranteeing the success rate of sensitive operations such as cell culture and sterile testing. It is recommended to establish an electronic ledger system to record real-time usage time, filter replacement dates, and various testing results, achieving full traceability management.