1. Test Method

The method adopts the counting concentration method, that is, by collecting the biological particles suspended in the air in a special medium, and allowing them to be propagated to visible colonies under suitable growth conditions for counting for a certain period of time, thereby determining the clean environment. The number of living microorganisms per unit volume of air is used to assess the cleanliness of the clean room (zone).

2. Experimental equipment

( a ) Airborne bacteria sampler, Tianjin Hengao Technology Development Co., Ltd.;

( b ) Petri dishes;

( c ) Constant temperature incubator.

3. Test preparation matters

(1) Medium

Ordinary broth agar medium or other Pharmacopoeia approved medium. Its preparation method can be seen

standard.

(2) Constant temperature incubator

The thermometer of the incubator must be checked regularly.

4. Test steps

(1) The surface of the instrument and the culture dish must be strictly disinfected before testing.

(2) Sampling

(3) Cultivation

( a ) After the sampling is completed, the culture dish is placed in a constant temperature incubator for cultivation.

( b ) Incubate in an incubator at 30 °C to 35 °C for a period of not less than 48 hours .

( c ) Each batch of medium should have a control test to check whether the medium itself is contaminated. Three culture dishes can be selected for each batch for control culture.

( d ) colony count

i The naked eye counts directly, marks or counts on the colony counter, and then checks with a 5 to 10 times magnifying glass to see if it is missing.

ii board has two or more overlapping two colonies, still two or more than two distinguishable colony count.

5. Notes

(1) Carefully check the quality of each dish before use. The medium and dish are deteriorated, damaged or contaminated and cannot be used.

(2) Take all measures to prevent contamination of the sampling tube and other artificial contamination of the sample.

(3) The media, culture conditions and other parameters were recorded in detail.

(4) Due to the wide variety of bacteria, the difference is very large. When counting, generally use the transmitted light to observe carefully on the back or front of the culture dish. Do not miss the colonies growing on the edge of the culture dish, and pay attention to the difference of bacterial colonies or medium sediments. If necessary, use a microscope. Identification.