Tris

Tris, or tris(hydroxymethyl)aminomethane, or known during medical use as tromethamine or THAM, is an <a href="/facts/Organic_compound/gqCNaN45">organic compound</a> with the formula (HOCH2)3CNH2. It is extensively used in <a href="/facts/Biochemistry/fa2pWEBp">biochemistry</a> and <a href="/facts/Molecular_biology/YgqU35ub">molecular biology</a> as a component of <a href="/facts/Buffer_solution/zrLz9eaa">buffer solutions</a> such as in <a href="/facts/TAE_buffer/Embv1Xpu">TAE</a> and <a href="/facts/TBE_buffer/RmYhCdGd">TBE buffers</a>, especially for solutions of <a href="/facts/Nucleic_acid/2tTgcI0v">nucleic acids</a>. It contains a <a href="/facts/Primary_amine/SN7W44fv">primary amine</a> and thus undergoes the reactions associated with typical amines, e.g., condensations with <a href="/facts/Aldehydes/xSIRkW03">aldehydes</a>. Tris also complexes with metal ions in solution. In medicine, tromethamine is occasionally used as a drug, given in intensive care for its properties as a buffer for the treatment of severe <a href="/facts/Metabolic_acidosis/sSKCKBHA">metabolic acidosis</a> in specific circumstances. Some medications are formulated as the "tromethamine salt" including <a href="/facts/Hemabate/GpoNjJXG">Hemabate</a> (<a href="/facts/Carboprost/GpoNjJXG">carboprost</a> as trometamol salt), and "<a href="/facts/Ketorolac/rakTnlbx">ketorolac</a> trometamol". In 2023 a strain of <a href="/facts/Pseudomonas/FKEX7p7K">Pseudomonas</a> hunanensis was found to be able to degrade TRIS buffer.
Since Tris' pKa is more strongly temperature dependent, its use is not recommended in biochemical applications requiring consistent pH over a range of temperatures. Moreover, the temperature dependance of the pKa (and in turn buffer solution pH) makes pH adjustment difficult. (E.g., the 'room temperature' pH adjustment would not translate to 'measurement conditions' pH, unless care is taken to calculate the effect of temperature, see below.)

Tris open-in-new

Tris