Tris acetate formula
Required materials
1. ** Tris base **: As the main buffer component, it is used to adjust the pH of the solution.
2. ** glacial acetic acid **: Provide an acidic environment and interact with Tris base to form a buffer system.
3. ** Disodium ethylenediamine tetraacetate (EDTA) **: Usually used for chelating metal ions, it helps to maintain the stability of the solution and certain specific reaction environments in this formulation system.

Operation steps
1. ** Prepare a suitable container **: Select a clean and suitable capacity glass beaker or plastic container for subsequent mixing of reagents.
2. ** Weigh Tris base **: Accurately weigh the appropriate amount of Tris base according to the concentration and volume of the desired configuration solution. For example, to configure 1L of Tris-acetate buffer with a concentration of 0.5M, accurately weigh 60.57g of Tris base (Tris base molecular weight is about 121.14g/mol). Carefully pour the weighed Tris base into the prepared container.
3. ** Add glacial acetic acid **: Slowly add glacial acetic acid to the container containing Tris base according to the formula ratio. For example, for the above 1L 0.5M Tris-acetate buffer, if the formula requires the acetic acid concentration to be 0.1M, the required amount is 5.71mL glacial acetic acid (glacial acetic acid density is about 1.05g/mL, molecular weight is 60.05g/mol). During the addition process, pay attention to stirring while adding to promote its initial mixing.
4. ** Add EDTA **: According to actual needs, weigh an appropriate amount of EDTA disodium and add it to the container. A prajna requires the final EDTA concentration to be 0.01M. When configuring 1L of solution, weigh 3.72g EDTA disodium (EDTA disodium molecular weight is about 372.24g/mol). Stir well to completely dissolve EDTA disodium.
5. ** bandwidth evaluation **: Slowly add deionized water to the container. When approaching the desired volume, change to a dropper and add it carefully until the solution volume accurately reaches the target value, such as 1L in the above example.
6. ** Adjust pH **: Use a precision pH meter to measure the pH of the solution and fine-tune it with dilute acetic acid or sodium hydroxide solution until the specific pH required for the formula is reached, commonly such as pH 7.4 - 8.0, etc., to meet the needs of different experiments or application scenarios.
7. ** Filtration and sterilization (if necessary) **: If the Tris acetate solution is used in scenes with high sterility requirements such as cell culture and molecular biology experiments, it needs to be filtered and sterilized through a filter membrane of 0.22μm or 0.45μm, and the filtrate should be collected in a sterile container for later use.

Precautions
1. ** Reagent purity **: Make sure that the reagents used such as Tris base, glacial acetic acid and EDTA disodium are of analytical purity or higher purity to avoid impurities interfering with the experimental results.
2. ** Safe operation **: Glacial acetic acid has a corrosive and irritating odor. Protective gloves, goggles and other protective equipment should be worn during operation and carried out in a well-ventilated environment.
3. ** Storage conditions **: The configured Tris acetate solution should be sealed and stored in a suitable temperature environment. Generally, it is appropriate to refrigerate at 4 ° C. If it is stored for a long time and sensitive to microbial contamination, an appropriate amount of bacteriostatic agent can be added. At the same time, regularly check whether the solution has abnormal phenomena such as precipitation and discoloration. If so, it should not be used again.