The function and preparation of Tris buffer

Details:

Buffer solution is a water-based solution containing weak acid and its conjugated base. Due to the chemical properties of buffer solution, even if the substance changes chemically, buffer solution can keep its pH value (acidity) at almost constant level. Buffer naturally exists in the plasma, which keeps the blood pH between 7.35 and 7.45. In organic systems, natural buffers keep the pH at a consistent level. But in the process of biological research, the pH value must be kept constant by buffer solution. There are many kinds of buffers, Tris buffer is one of the commonly used biological buffers.

What is Tris buffer

Tris is the abbreviation of tris (hydroxymethyl) aminomethane, which is a compound commonly used in brine. Because it is isotonic and non-toxic, PKA is 8.1, and pH value is between 7 and 9, Tris buffer solution is also commonly used in a series of chemical analysis and biological research, including DNA extraction. It is important to know that the pH value in Tris buffer solution varies with the solution temperature.

How to prepare Tris buffer

Preparation of Tris buffer is very simple, only the following materials are prepared

● tris (hydroxymethyl) aminomethane (Tris)  

Distilled deionized water

Hydrochloric acid

step

1. First, determine the concentration (molar concentration) and volume of Tris buffer you want to make. For example, Tris buffer solutions for normal saline range from 10 to 100 mm. According to the experimental requirements, the molar number of Tris was calculated by multiplying the molar concentration of the buffer by the volume of the buffer being prepared（ Mole number of Tris = mol / L x L)

2. Next, determine what gram this is by multiplying the number of moles by the molecular weight of tris (121.14 g / mol). The number of moles of Tris = (mol) x (121.14 g / mol)

3. Dissolve Tris in distilled deionized water to 1 / 3 to 1 / 2 of the final volume required.

4. Mix in HCl (e.g. 1m HCl) until the pH meter provides the required pH for your Tris buffer solution.

5. Dilute the buffer with water to achieve the required final volume of solution.