The TRIS-HCL buffer is stable. It can be widely used in the preparation of buffers in biochemistry and molecular biology experiments. It has good compatibility with physiological body fluids and will not form precipitates with calcium and magnesium ions. On the contrary, phosphate and calcium and magnesium ions will produce precipitation. Moreover, the ionic strength of TRIS-HCL buffer with the same pH and same concentration is lower than that of phosphate buffer. This is particularly important for enzyme determination. Because of the high ionic strength, some enzymes are easily inactivated. Therefore, sometimes using TRIS-HCL instead of phosphate buffer, the effect is better.
However, the pH of TRIS-HCL buffer is greatly affected by temperature. Once the temperature changes, the pH will change significantly. The problem of causing changes in enzyme activity has not attracted enough attention from the clinical laboratory. For this reason, we measured the temperature coefficient of TRIS-HCL buffer and discussed its practical value. The Tris reagent used in the following experiment was developed and produced by Tecsun Technology.
Desheng TRIS buffer packaging
Experimental process: Put the TRIS-HCL buffer in a 37℃ water bath for 30 minutes. Distilled water, the calibration solution remains at room temperature. Place the temperature knob at 37°C, and take out the buffer after equilibrating the temperature. Adjust zero with distilled water at room temperature, calibrate with mixed phosphate at room temperature (pH 6.84 at 37°C), and immediately determine the pH of the TRIS-HCL buffer. The buffer is placed at room temperature until the temperature drops to 23°C. Adjust to zero with distilled water at room temperature. Calibration of mixed phosphate at room temperature (pH 6.86 at 23°C), and then immediately determine the corresponding pH. The solution was kept at room temperature. Wait until the temperature drops to room temperature. Adjust the temperature knob again. Calibrate and determine the pH at room temperature.
Experimental results: According to the above method, the pH at 37°C is on average 0.18 lower than the pH at 23°C. The pH is 0.32 lower than the pH at l2℃ on average. Temperature changes have a great influence on the pH of the buffer, so it must be prepared at the operating temperature. Tris-HCl buffer prepared at room temperature cannot be used at 0℃～4 ℃.
Therefore, the pH of the TRIS-HCL buffer is greatly affected by temperature changes. When measured by different methods, the changes are different. The pH changes of the two temperatures (37°C, 23°C) have nothing to do with the measurement method. We speculate that to determine the pH value of a solution at a certain temperature. It is necessary to adjust not only the temperature compensation value of the pH meter but also all the various solutions and distilled water to the measurement temperature.
