The aseptic room shall be kept clean. Storing extraneous items is prohibited to prevent contamination. All sterilization equipment and media must be strictly protected from contamination; any contaminated items or equipment must be discontinued immediately. The aseptic room shall be equipped with disinfectants at working concentrations, such as 5% cresol solution, 70% ethanol, and 0.1% neomycin solution. The aseptic room shall be regularly disinfected and cleaned with appropriate disinfectants to ensure that its cleanliness meets the required standards.

All instruments, equipment, dishes, and other items to be brought into the aseptic chamber must be securely packaged and properly sterilized. Prior to use, the ultraviolet lamp should be turned on to disinfect the aseptic chamber for at least 30 minutes, and the laminar flow hood should be activated to blow air. After completing the procedure, the aseptic chamber should be promptly cleaned and then disinfected with the ultraviolet lamp for an additional 20 minutes. Before testing, ensure that the test product’s outer packaging remains intact and unopened to prevent contamination. Prior to inspection, disinfect the exterior surface with an alcohol‑impregnated cotton swab containing 70% ethanol.

Each time an operation is performed, a negative control should be included to verify the reliability of aseptic technique. When aspirating bacterial suspension, use a rubber bulb; do not allow the pipette tip to come into direct contact with your mouth. The inoculating needle must be flame‑sterilized before and after each use, and inoculation may proceed only after the culture medium has cooled. Pipettes, test tubes, petri dishes, and other vessels containing bacterial suspensions should be immersed in a disinfectant bucket containing 5% lysol for sterilization, then removed and rinsed after 24 hours. If any bacterial solution is spilled on a table or the floor, immediately treat the contaminated area by applying a 5% carbonate solution or 3% lysol and allow it to act for at least 30 minutes before disposal. When work uniforms or caps become contaminated with bacteria, they should be promptly removed, autoclaved under high pressure, and washed. All items containing live cultures must be disinfected before being rinsed under running water. Contamination of the sewer system is strictly prohibited.

The aseptic room shall be inspected monthly for colony counts. Petri dishes are placed at designated workstations and other locations; after exposure, the lids are left open for 30 minutes, then the plates are inverted and incubated in a 30–35°C incubator for 48 hours before being removed for examination. In a Class 100 cleanroom, the average number of colonies on agar plates must not exceed one; in a Class 10,000 cleanroom, the average must not exceed three. If these limits are exceeded, the aseptic room must be disinfected until repeated testing confirms compliance.

Cleanroom air purification is a type of bio‑cleaning engineering. Typically, cleanrooms are required to meet Class 10,000 cleanliness standards. Standard microbiological testing laboratories usually designate a dedicated cleanroom measuring 5 to 8 square meters. As long as the space is sufficient to accommodate laboratory samples and essential equipment, an excessively large area should be avoided to prevent waste; overly spacious cleanrooms not only increase construction costs but also lead to significantly higher operational and maintenance expenses. In accordance with laboratory industry requirements, most microbiological tests must be conducted within a cleanroom. Many bacteria and microorganisms found in food products are detected and quantified using a laminar flow hood.

With the advancement of science and technology, governments are placing increasing emphasis on food safety, and cleanroom air‑purification systems are becoming ever more widespread. In conjunction with cleanroom purification, a laminar flow hood is typically installed within the cleanroom to facilitate operations, ensuring a cleaner experimental environment and minimizing the risk of sample contamination.