Practical Techniques of Preloading Culture Medium Plate with Finished Products

      

　　Turbulence clean area

　　The clean air in the turbulent clean room enters the room through the diffusion cover that sends the trend through the outlet of the high-efficiency filter, and the clean air quickly spreads around, mixes with the indoor air, dilutes the indoor polluted air, and exchanges with the indoor heat load. The mixed air flow carries the indoor dust, and is discharged from the trend under the action of the positive air pressure, as shown below:

　　The airflow organization of a turbulent clean room mainly includes four types:

　　The air supply on the top of the orifice plate is divided into the air supply on the top of the whole orifice plate and the air supply on the top of the local orifice plate.

　　Streamlined diffuser top air supply, this air flow organization is suitable for high plants above 4 meters.

　　The trend diffusion top air supply of high efficiency filter is a commonly used form of airflow organization in clean areas for production.

　　Side air supply. This form is suitable for plants with lower floor heights, and is mostly used for the renovation of old plants. There are many eddies in the side air supply room, and the cleanliness can only reach Class C.

　　Air supply and ventilation times in the clean area

　　As mentioned earlier, the key indicator to distinguish a turbulent clean area or a one-way flow clean area is the flow state of the air in the clean area, and the flow state of the air is determined by the flow mode and speed of the air. Therefore, the amount of clean air per unit time in a specified size space plays a decisive role in cleanliness. The table below shows the relationship between the number of cleanroom operators, the number of air changes and the cleanliness of the room.

　　Note:

　　The lower limit of the number of indoor ventilation is 30 minutes, and the cleanliness needs to reach 80%.

　　One-way flow (laminar flow) clean area air supply = clean area (m2) X wind speed;

　　Turbulent flow (non-unidirectional flow) clean area air supply = clean area volume (m3) X number of ventilation (times/h).

　　The number of ventilation times in the clean area environment of drug production should be verified and determined according to the calculation of heat balance and air volume balance with reference to the regulations on the number of ventilation times.

　　Sources of microbial contamination in clean areas

　　Microbial contamination refers to the production of microorganisms that adhere to a specific environment and cause adverse effects. If bacteria are given the necessary nutrients, a certain amount of moisture and the right temperature and humidity, they can multiply rapidly, and their reproduction rate is very fast, thus causing harm to the clean area where production is carried out. Clean area pollution can be divided into two types of pollution. The first is the pollution of inorganic substances (lifeless), such as suspended particles in the air and particles on materials; the second is organic pollution, such as microorganisms. There are five main sources of microbial pollution: personnel, equipment, materials, air and water.

　　(1) Pollution of personnel

　　As we all know, people are the main source of pollution in clean areas, and human contamination of clean areas is a never-ending process. Skin chips, hair, microorganisms in the human body, etc.

　　Bacteria per minute

　　Sneezing 12 - 3400

　　Coughing 1 - 1000

　　Singing 1 - 128

　　Speech 1 - 28

　　Calm Breathing 0 - 4

　　Take clean area operators as an example:

　　When sitting or standing still, the number of particles per minute is as high as 100,000 (10,000/min).

　　When sitting for moderate body and arm movements, the number of particles can reach half a million (50,000/min).

　　The number of particles during normal walking is as high as 2.5 million (250,000/min).

　　Up to 10 million particles when walking fast (1,000,000/min)

　　The number of particulates during installation and maintenance work is as high as 30 million (3,000,000/min).

　　The human body is home to more than 100 billion microorganisms, with as many as 400 species, distributed in various parts of the body.

　　Oral cavity:

　　1 ml of saliva has more than 100 million bacteria, mainly Escherichia coli, fragile bacteria, anaerobic

　　Sex cocci and lactobacillus can form again within 6 hours after the bacteria in the mouth are cleared.

　　Skin:

　　The surface of the skin is replaced every four days, shedding 4-6 grams of skin chips every day, each skin chip is composed of about 4 bacteria,

　　Mainly have Staphylococcus epidermidis, Staphylococcus aureus.