A 10X Tris-MES buffer solution, pH 7.3, is a concentrated stock solution combining two buffering agents, Tris and MES, designed to maintain a stable pH of approximately 7.3 in biological and biochemical applications, particularly protein electrophoresis. This denotes a 10-fold concentrated stock solution. It is prepared at a higher concentration for convenience of storage and stability. Before use in experiments, it must be diluted with deionized or nuclease-free water to its working concentration (1X). For example, to make 1 liter of 1X solution, you would mix 100 mL of the 10X stock with 900 mL of water.