The pH values of all buffers are temperature and concentration dependent. For Tris buffers, pH increases about 0.03 unit per °C decrease in temperature, and decreases 0.03-0.05 unit per ten-fold dilution.
For precise applications, use a carefully calibrated pH meter with a glass/calomel combination electrode.
Tris HCl is a commonly used biological buffer. Tris/Tris HCl as a buffering system has a very broad usage in biological systems for biopharmaceutical manufacturing, cell culture, diagnostics and molecular biology. The pKa of Tris is 7.77 which corresponds closely to a physiological pH of 7.36.
Tris HCl is used as the conjugate buffer component with Tris/Tromethamine/Trizma in biopharmaceutical buffer formulations (both upstream and downstream applications), electrophoresis separations and diagnostic reagent formulations.