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Guide: Before using the new bottle, it should be simply brushed with tap water, then soaked in dilute hydrochloric acid solution (5%) overnight...
1. Washing of glassware
The new bottle should be simply washed with tap water before use, and then soaked in dilute hydrochloric acid solution (5%) overnight. The cultured glassware should be immersed in clean water immediately after use.
Note: Allow the water to fully enter the bottle without leaving air bubbles.
The soaked glassware should be washed with a brush dipped in detergent (soft brushes and high-quality detergents should be used, such as high-grade washing powder or detergent), and sand-containing decontamination powder must not be used! When washing, pay special attention to the corners of the bottle.
The vessel should be filled with cleaning solution without leaving air bubbles. The soaking time shouldn't be less than 6 hours; generally it should be soaked overnight.
Cleaning fluid formula:
【Strong Liquid】Potassium Dichromate 63g
Concentrated sulfuric acid 1000ml
Distilled water 200L
【Secondary Strength】Potassium Dichromate 120g
Concentrated sulfuric acid 200ml
Distilled water 1000ml
【Weak Liquid】Potassium Dichromate 100g
Concentrated sulfuric acid 100ml
Distilled water 100ml
Sodium silicate lotion;
It is safer to use and can replace cleaning fluid, but it is more expensive. Firstly prepare 100X stock solution: 80g potassium silicate, 9g sodium metaphosphate, heat and dissolve in 1000ml distilled water. When using, dilute 100 times with distilled water.
After brushing and pickling, it must be thoroughly rinsed with water so that no residue is left. A washing device should be used for rinsing to ensure the rinsing effect. If manual operation is used, each bottle must be filled with water, poured out and repeated more than ten times. Finally rinsed with distilled water for 2 to 3 times then dried for later use.
2. Cleaning of rubber stopper
Rinse the newly purchased rubber stopper with tap water first, doing the conventional treatment next.
Regular washing method:
Soaking - 2% NaOH boil (10-20 minutes) - tap water rinse - 1% dilute hydrochloric acid soaking (30 minutes) - tap water rinse - distilled water cleaning (2-3 times) - dry for use
3. Cleaning of plastic utensils
At present, the plastic utensils used for cultivation in my country are mainly purchased from abroad, which are non-toxic and have been sterilized and sealed in a sealed package. When using, just open the package, it is a one-time use item. It can be used repeatedly 2 to 3 times after aseptic treatment used if necessary, but it should not be too much. Cleaning and sterilization are still required for reuse. Plastic apparatuses are soft in texture and should not be washed with a brush make cleaning difficult. For this purpose, one is to prevent scratches, the other is to immerse it in water immediately after use to prevent the adhesion from drying out. If there is any residual adhesion, it can be wiped off with absorbent cotton, rinsed with running water, dried. Then use 2% NaOH solution Soak overnight, fully rinse with tap water, and soaking in 5% hydrochloric acid solution for 30 minutes. Rinsing with tap water and distilled water and dry it for later use at last.
4. Ultraviolet disinfection
The direct ultraviolet irradiation method is very convenient and effective. It is currently a commonly used disinfection method in various laboratories.
【Scope of application】Air, the surface of the operating table and some culture vessels that cannot be sterilized by other methods (such as plastic culture dishes, culture plates, etc.)
【Requirements】(1) The ultraviolet lamp in the cultivation room should be 2.5 meters away from the ground, so that there is 0.06 microwatts of energy per square centimeter for effective disinfection can be occured. (2) Due to the different sensitivities of various bacteria to ultraviolet rays, the irradiation time and dose used are also different.
【Disadvantages】(1) It produces ozone, pollutes the air and is harmful to the body; (2) The parts that cannot be irradiated by rays cannot be disinfected, so items shouldn't be shielded from each other during disinfection.
【Note】Some people are accustomed to performing experimental operations while irradiating that isn't good. intially ultraviolet rays have adverse effects on cells, reagents and culture medium; They also damage human skin, secondly.
5. Moist heat disinfection
Moist heat sterilization, namely high pressure steam sterilization is the most effective method.
【Scope of application】Cloths, rubber stoppers, metal instruments, glassware and some culture liquids.
Culture liquid, rubber products 10 pounds 10 minutes
Cloth, glass products, metal equipment, etc. 15 pounds 20 minutes
6. Filtration and disinfection
【Scope of application】Most of the culture fluids, such as synthetic culture fluid, serum, enzyme solution, etc. (these will be denatured at high temperature and lose their function, and must be sterilized by filtration.
【Commonly used filters】Zeiss filters, microporous membrane filters and disposable filters of various specifications. Commonly used pore size 0.22um filter membrane can filter general liquid.
(1) The filter membrane is discarded after use, and the filter cleaning is also more convenient. First, use a brush dipped in detergent to clean it, rinse it with tap water, then rinse it with distilled water, let it dry;
(2) Install a new filter membrane before use;
(3) Don't twist the knob too tightly during disinfection, wrapping all parts in contact with air with paper to ensure the effect of disinfection;
(4) After sterilization, tighten the knob immediately in a sterile environment;
(5) When filtering a small amount of liquid, use a small filter that can be installed on a syringe and use the same filter membrane. When filtering, put the filtrate into the syringe needle, and press out the filtrate to inject it into a sterile container.