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The most complete laboratory equipment cleaning method

In the face of large and small experimental instruments in the laboratory, cleaning is definitely a laborious and laborious task. If the method is not selected correctly, it will get twice the result with half the effort. How to choose the method will get twice the result with half the effort? Below I will introduce several methods for your reference:

Decontamination of new glassware
1. Brush with tap water to remove dust.
2. Drying and soaking in hydrochloric acid: Dry in an oven, and then immerse in 5% dilute hydrochloric acid for 12 hours to remove dirt, lead, arsenic, etc.
3. Scrubbing and drying: Rinse with tap water immediately after 12 hours, then scrub with detergent, rinse with tap water and dry in an oven.
4. Acid soaking and cleaning: soak in cleaning solution (120g potassium dichromate: 200ml concentrated sulfuric acid: 1000ml distilled water) for 12 hours, then remove the utensils from the acid tank and rinse with tap water 15 times, and finally rinse with distilled water 3-5 times and Use double distilled water 3 times.
5. Drying and packaging: dry first after washing, and then package with kraft paper (glossy paper).
6. High-pressure sterilization: Put the packaged utensils into the pressure cooker, close the lid, 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 for 20-30 minutes.
7. Dry after autoclaving.

Decontamination pictures of old glassware
1. Scrubbing and drying: The used glassware can be directly soaked in Lysur solution or detergent solution, and the utensils soaked in Sur solution (detergent) should be cleaned with clean water and then dried.
2. Acid soaking and cleaning: After drying, soak in the cleaning solution (acid solution), remove the utensils from the acid tank after 12 hours and rinse them with tap water immediately (to avoid the protein adhering to the glass after drying and difficult to clean), and then use distilled water Rinse 3 times.
3. Drying and packaging: After the cleaned utensils are dried, they are packaged with kraft paper (glossy paper) to facilitate disinfection and storage and prevent dust and re-contamination.
4. High pressure sterilization: put the packaged utensils into the pressure cooker, close the lid, open the switch and safety valve, the safety valve will emit steam as the temperature rises, when the steam emerges in a straight line for 3-5 minutes, close the safety valve , The barometer index rises accordingly. When the pointer points to 15 pounds, adjust the electric switch to maintain it for 20-30 minutes. (Before disinfecting the glass culture flask, you can gently cover the plastic cap).
5. Drying for standby: Because the utensils will be wetted by steam after autoclaving, they should be dried in the oven for standby.

Decontamination of metal equipment
Metal utensils should not be soaked in acid. You can wash them with detergent first, then rinse with tap water, then wipe with 75% alcohol, then rinse with tap water, then distilled water, and then dry or air dry. Put it in an aluminum box, pack it, and sterilize it in a pressure cooker with 15 pounds of high pressure (30 minutes), and then dry it for later use.

Rubber and plastic:
The usual processing method for rubber and products is: first wash it with detergent, then rinse it with tap water and distilled water, and then dry it in an oven, and then perform the following processing procedures according to different qualities:
1. The needle filter cap can not be soaked in acid liquid, soak in NaOH for 6-12 hours, or boil for 20 minutes. Before packaging, install two filter membranes. When installing the filter membrane, pay attention to the light side up (concave upward), and then Loosen the screw slightly, put it in an aluminum box, sterilize it in a pressure cooker for 15 pounds for 30 minutes, and then dry it for later use. Note that the screw should be tightened immediately when it is taken out of the clean bench for use.
2. After the rubber stopper is dried, boil it with 2% sodium hydroxide solution for 30 minutes (the used rubber stopper only needs to be treated with boiling water for 30 minutes), rinse with tap water, and dry. Then soak in the hydrochloric acid solution for 30 minutes, then rinse with tap water, distilled water, and three-distilled water, and dry. Finally, put it into an aluminum box for autoclaving and drying for later use.
3. After drying, the plastic caps and centrifuge tube caps can only be soaked in 2% sodium hydroxide solution for 6-12 hours (remember that the time should not be too long), rinsed with tap water, and dried. Then soak in the hydrochloric acid solution for 30 minutes, then rinse with tap water, distilled water, and three-distilled water, and dry. Finally, put it into an aluminum box for autoclaving and drying for later use.
4. The plastic head can be soaked in 75% alcohol for 5 minutes, and then used after UV irradiation.
5. Other disinfection methods: Some items can neither be dried nor steam sterilized, and can be disinfected by soaking in 70% alcohol. Open the lid of the plastic petri dish, place it on the ultra-clean table, and directly expose it to ultraviolet light for sterilization. Ethylene oxide can also be used to disinfect plastic products. After disinfection, it takes 2-3 weeks to wash away the residual ethylene oxide. It is best to use 20,000-100000rad r-ray to sterilize plastic products.
In order to prevent the confusion between disinfected and undisinfected cleaning equipment, after the paper packaging, use steganographic ink to make a mark. The method is to use a dipping pen or brush with steganographic ink and make a mark on the wrapping paper. Normally, the ink has no traces. When the temperature is high, the writing will appear, so that it can be judged whether they are disinfected. The preparation of steganography ink: Chlorinated cobalt (CoC12•6H2O) 2g, 30% hydrochloric acid 10mL, distilled water 88mL.
Precautions:
1. Strictly implement the operating procedures of the pressure cooker: When autoclaving, first check whether there is distilled water in the pot 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 unobstructed to prevent explosion at high pressure.
2. When installing the filter membrane, pay attention to the shiny side facing up: note that the smooth side of the filter membrane is the front side, and it should be facing up, otherwise it will not be able to filter.
3. Pay attention to the protection of the human body and the complete immersion of the utensils:
A. Wear acid-resistant gloves when soaking acid to prevent the acid from splashing and hurting the human body.
B. When picking out utensils from the acid tank, prevent the acid from splashing on the ground, which will corrode the ground.
C. The utensils must be completely immersed in the acid solution, and no bubbles should be left to prevent incomplete soaking of the acid.