Views: 4 Author: Site Editor Publish Time: 2024-05-29 Origin: Site
How to verify the sterilization effect of pressure steam sterilizer
1.Test materials
① Bacillus thermophilus paper sheet; Bacillus thermophila ATCC7053, containing 5-105 CFU/piece of spores
② 121℃ pressure steam sterilization chemical instruction card; bromocresol peptone water culture medium, 116℃ for 20 minutes after high pressure for use.
③ 0-150℃ leaving point thermometer
2. Methods and results
Place the Bacillus thermophilus paper piece into a sealed test tube using sterile forceps. The chemical indicator card and retention thermometer are placed in the open test tube. Prepare 5-10 copies of each of the above two test tubes. Place them at the steam port, bottom exhaust port and bottom water port of the pressure steamer or 5 places in the middle, up, down, left, right and middle. If the pressure steamer has two floors, 10 places need to be placed. The remaining point thermometer can be used for verification tests after passing the standardization. Before testing, the mercury column of the thermometer needs to be thrown below 40°C. After each monitoring, the temperature difference of the remaining thermometer should be between 1°C, which indicates that the temperature distribution in the pressure steamer is uniform. The bacterial slices should be placed in the bromocresol peptone water culture medium behind the human body under strict sterile operating conditions. Incubate at 56-60℃ for 24-48 hours and observe color changes. If the culture medium turns yellow, it means that the thermophilic Bacillus in the bacteria piece has not been completely inactivated. The bacteria can still grow in the culture medium, decompose glucose and produce acid, which turns yellow. If the color of the culture medium does not change and remains purple, it means that the spores have been inactivated. At the same time, an unused piece of paper should be placed in the medium as a positive control, and a blank medium without paper should be used as a negative control. The indicator color block on the chemical indicator card changes from light yellow to black when the pressure steamer is used. As the color changes and compared with the control color, you can judge whether the effect meets the requirements. Chemical indicator cards should be stored in a dry place. It will change color when exposed to tide, affecting the observation of the effect. A pressure steamer must allow the steam to smoothly enter the device, contact the items, and discharge the original cold air to achieve the desired effect. It is necessary to verify the no-load heat distribution and full-load heat penetration (not exceeding 2/3 of the total volume when fully loaded). Each of the two verifications was repeated three times, making a total of six tables. Six tests at 5 points showed that the temperature was all at 121°C, and the chemical indicator card turned black; the degree was consistent with the control color; the medium did not change color, indicating that the pressure steamer was qualified.