Introduction
Due to the different raw materials of the culture medium, the use requirements are different, and the storage and storage are also slightly different. The general culture medium is easily contaminated by bacteria or decomposes and deteriorates after being heated and absorbed moisture. Therefore, the general culture medium must be kept in a moisture-proof, dark and cool place. For some mediums that require strict sterilization (such as tissue culture medium), long-term storage must be placed in a refrigerator at 2 ~ 6 ℃. Since the liquid medium is not easy to store for a long time, it is now converted into powder.
Preparation of medium
1. Ingredients
Recipe conversion → Add a small amount of water [distilled water, natural water] to the container → Weigh various medicines according to the recipe [sequential addition] → Add the required amount of water "one spoonful of medicine, cover the bottle immediately after taking medicine"
2. Dissolve
Starch dissolution: a small amount of cold water is adjusted to a paste
Heat to dissolve, especially the medium with agar added, it must be boiled, the melting temperature of agar is 95 ～ 97 ℃,
Stir while heating to prevent scorching.
3. Adjust the PH
Adjust the medium to the desired value with 1N hydrochloric acid or 1N NaOH.
4. Filter
Filter with paper or cotton.
5. Packing
Generally, the medium is sterilized in a triangular flask or test tube.
(1) Triangle bottle
For static cultivation, the 100 ml medium / 250 ml Erlenmeyer flask cannot exceed 150 ml medium / 250 ml
Erlenmeyer flask, otherwise the medium may easily contaminate the tampon during sterilization and cause bacterial infection; if it is used for shake flask culture, 15 ～ 20 ml medium / 250
The triangle bottle of ml guarantees good ventilation.
(2) Separate test tubes
The liquid culture medium is generally filled with 4 to 5 ml, about 1/4 of the height of the test tube;
The solid slant medium is generally filled with 3 to 4 ml, about 1/5 of the height of the test tube.
6. Bandage
After sub-packing, plug the tampon and wrap the tampon with kraft paper to prevent moisture from entering and humidifying the tampon during sterilization.
7. Sterilization
Carry out high-pressure steam sterilization according to the temperature and pressure required in the formula. If the sterilization temperature is too high, the nutrients will be destroyed and cultivated
Sugars and amino acids in the base will darken the medium.
8. Pendulum
After sterilization, the test tube that needs to be inclined must be placed diagonally while it is hot, so that it solidifies to become an inclined surface, accounting for about 1/2 of the length of the test tube.
True & Bright Metal Packaging Co.,Ltd.KaiPing , https://www.tnbcan.com