Tris or THAM is an abbreviation for the organic compound known as tris (hydroxymethyl) aminomethane. The compound has two major uses: one in biochemistry and one in molecular biology. In biochemistry, it is mainly utilized as a component in buffer solutions, such as TBE and TAE solutions. In most cases, it is used as a buffer in nucleic acid solutions. Because THAM is a primary amine, it undergoes similar reactions, such as condensation reactions with aldehyde compounds. In the lab, the compound is also commonly used to standardize acid solutions in order to further analyze the solution. Medically speaking, Tris can be used as a substitute for sodium bicarbonate in treating metabolic acidosis. It is such a useful compound, because it maintains a buffer range of pH 7 to 9. This particular range coincides with the physiological pH range in most living organisms. Tris is also commonly used to increase the membrane permeability of cell membranes.