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Cleaning and disinfection of instruments during cell culture

Cleaning and disinfection of instruments during cell culture

1. Glassware washing

Disinfection of new glassware

1. Brush with tap water to remove dust.

2. Drying and soaking in hydrochloric acid: dry in the oven, and then immerse in 5% dilute hydrochloric acid for 12 hours to remove dirt, lead, arsenic and other substances.

3. Brushing and drying: wash with tap water immediately after 12 hours, then scrub with detergent, wash with tap water and then dry in the oven.

4. Pickling and cleaning: soak in cleaning solution (120g of potassium dichromate: 200ml of concentrated sulfuric acid: 1000ml of distilled water) for 12 hours, then remove the utensils from the acid tank and wash them with tap water for 15 times, and finally wash them with distilled water for 3-5 times and double distilled water for 3 times.

5. Drying and packaging: After cleaning, dry it first, and then pack it with kraft paper (glossy paper).

6. High-pressure disinfection: put the packed utensils into the pressure cooker and cover it. Open the switch and safety valve. When the steam rises in a straight line, close the safety valve. When the pointer points to 15 pounds, maintain it for 20-30 minutes.

7. Drying after high-pressure disinfection

 

Disinfection of old glassware

1. Brushing and drying: used glassware can be directly soaked in lysol solution or detergent solution. The glassware soaked in lysol solution (detergent) should be cleaned with clean water and then dried.

2. Pickling and cleaning: soak in cleaning solution (acid solution) after drying, remove the utensils from the acid tank after 12 hours, and immediately wash them with tap water (to prevent the protein from sticking to the glass after drying), and then wash them with distilled water for 3 times.

3. Drying and packaging: After drying, take out the cleaned utensils and use kraft paper (glossy paper) and other packaging to facilitate disinfection and storage and prevent dust and re-pollution.

4. High-pressure disinfection: put the packed utensils into the high-pressure cooker, close the lid, open the switch and safety valve, and the safety valve emits steam as the temperature rises. When the steam rises in a straight line for 3-5 minutes, close the safety valve, and the barometer index will rise. When the pointer points to 15 pounds, adjust the electric switch for 20-30 minutes. (Gently cover the rubber cap before sterilization of the glass culture bottle)

5. Drying for standby: Because the utensils will be wetted by steam after high-pressure disinfection, they should be put into the oven for drying for standby.

 

Metal instrument cleaning

Metal utensils cannot be soaked in acid. When washing, they can be washed with detergent first, then washed with tap water, then wiped with 75% alcohol, then washed with tap water, then dried with distilled water or dried in the air. Put it in an aluminum box, pack it in a high-pressure cooker, sterilize it with 15 pounds of high pressure (30 minutes), and then dry it for standby.

 

Rubber and plastics

The usual treatment method for rubber and products is to wash them with detergent, wash them with tap water and distilled water respectively, and then dry them in the oven, and then carry out the following treatment procedures according to different quality:

1. The needle filter cap cannot soak in acid solution. Soak in NaOH for 6-12 hours, or boil for 20 minutes. Before packaging, install two pieces of filter film. Pay attention to the smooth side up (concave side up) when installing the filter film. Then unscrew the screw slightly, put it in an aluminum box, disinfect it in a high-pressure cooker for 15 pounds and 30 minutes, and then dry it for standby. Note that the screw should be tightened immediately when it is taken out of the ultra-clean table.

2. After drying the rubber stopper, boil it with 2% sodium hydroxide solution for 30 minutes (the used rubber stopper should be treated with boiling water for 30 minutes), wash it with tap water and dry it. Then soak in hydrochloric acid solution for 30 minutes, then wash with tap water, distilled water and three-steam water, and dry. Finally, put it into the aluminum box for high-pressure disinfection and drying for standby.

3. After drying, the rubber cap and centrifugal pipe cap can only be soaked in 2% sodium hydroxide solution for 6-12 hours (remember not to be too long), washed and dried with tap water. Then soak in hydrochloric acid solution for 30 minutes, then wash with tap water, distilled water and three-steam water, and dry. Finally, put it into the aluminum box for high-pressure disinfection and drying for standby.

4. The rubber head can be soaked in 75% alcohol for 5 minutes, and then used after ultraviolet irradiation.

5. Plastic culture bottle, culture plate, frozen storage tube.

6. Other disinfection methods: some articles can neither be sterilized dry nor sterilized by steam, and can be sterilized by soaking in 70% alcohol. Open the lid of the plastic culture dish, put it on the ultra-clean table top, and directly expose it to ultraviolet light for disinfection. Ethylene oxide can also be used to disinfect plastic products. It takes 2-3 weeks to wash the residual ethylene oxide after disinfection. The best effect is to disinfect plastic products with 20000-100000rad r rays. In order to prevent the confusion between disinfected and unsterilized cleaning equipment, the paper packaging can be marked with close-up ink. The method is to use a water pen or a writing brush to dip in the steganographic ink and make a mark on the packaging paper. Usually the ink does not have traces. Once the temperature is high, the handwriting will appear, so that it can be determined whether they are disinfected. Preparation of steganographic ink: 88ml distilled water, 2g chlorinated diamond (CoC126H2O), and 10ml of 30% hydrochloric acid.

matters needing attention:

1. Strictly implement the operating procedures of the pressure cooker: during high-pressure disinfection, check whether there is distilled water in the cooker to prevent it from drying under high pressure. Do not use too much water because it will block the flow of air and reduce the effect of high-pressure disinfection. Check whether the safety valve is unblocked to prevent explosion under high pressure.

2. When installing the filter membrane, pay attention to the smooth side facing up: pay attention to the smooth side of the filter membrane, which should be facing up, otherwise it will not play the role of filtering.

3. Pay attention to the protection of the human body and the complete immersion of the utensils: A. Wear acid-resistant gloves when foaming acid to prevent the acid splashing and hurting the human body. B. Prevent acid from splashing to the ground when taking utensils from the acid tank, which will corrode the ground. C. The utensils shall be completely immersed in the acid solution without bubbles to prevent incomplete acid foaming.


Post time: Feb-01-2023