Teach you how to verify the Portable Pressure Steam Sterilization effect of an autoclave!

The Portable Pressure Steam Sterilization effect verification of high-pressure steam sterilizer generally includes the chemical indicator method, the retention point thermometer method, the self-made temperature measuring tube method and the biological indicator method. The principles of the methods are similar, mainly through the verification of sterilization. Whether the temperature in the bacteria chamber can meet the requirements. We can choose one or more of these methods for verification according to the specific conditions of our own laboratory.

1. Chemical indicator method

3M pressure sterilization indicator tape is commonly used in general laboratories. This indicator tape uses the color change of the tape before and after sterilization to judge the sterilization effect. The indicator tape can be directly pasted on the outside of the package, the length is not less than 5cm, and lightly press the tape to increase the viscosity and sealing effect; after the tape is kept at 121°C for 20min or 130°C for 4min, the diagonal white indicator lines printed on the tape will be It turns black completely and becomes a black line; if the color is uneven or incomplete, it can be considered that the package does not meet the sterilization conditions.

2. Keep some thermometer method

When verifying, put the mercury thermometer in a large triangular flask containing water, and place the triangular flask on the upper and lower parts of the sterilizer during sterilization. After the sterilization, check whether the temperature of the mercury thermometer is consistent with the required temperature. This method can only verify the temperature and cannot indicate whether the sterilization time meets the requirements, so it is the minimum standard for sterilizer verification.

3.Self-made temperature measurement tube method

The commonly used reagent is benzoic acid. The melting point of benzoic acid is 121-123°C, which is basically consistent with the sterilization temperature of the sterilizer we require. Therefore, the solid benzoic acid is sealed in a small glass tube and placed into the sterilizer during sterilization. After sterilization, the state of benzoic acid can be observed to verify whether the sterilizer has reached the required temperature.

4. Biological indicator method

Biological indicators are divided into three types: spore suspension, spore sheet, bacteria sheet and medium mixed indicator tube. Generally placed in 5 points of the sterilization container: the front, middle, and back of the lower layer and the central point of the upper and middle layers. After sterilization, inoculate the indicator into bromocresol purple-glucose peptone water, and cultivate for 2-7 days at 55-60°C. If the medium is clear and the color does not change, it means that the spores have been killed, and the sterilization effect of the sterilizer is good; If the medium is yellow and turbid, it means that the spores have not been killed and the sterilization effect of the sterilizer is unqualified. The verification methods for spore suspension and spore sheet are the same.