Tris
496251
224177846
2008-07-07T17:58:23Z
198.176.189.201
/* Buffer details */
{{Chembox new
| Name = Tris
| ImageFile = Tris.png
| ImageSize = 160px
| ImageName = Chemical structure of tris
| IUPACName = 2-Amino-2-hydroxymethyl-propane-1,3-diol
| OtherNames = TRIS, Tris, Tris base, Tris buffer,<br />Trizma<sup>TM</sup>, Trisamine, THAM,<br />Tromethamine, Trometamol, Tromethane
| Section1 = {{Chembox Identifiers
| SMILES = C(C(CO)(CO)N)O
| CASNo = 77-86-1
| RTECS = TY2900000
}}
| Section2 = {{Chembox Properties
| C = 4
| H = 11
| N = 1
| O = 3
| Appearance = White crystalline powder
| Density =
| Solubility = 220 g/100 ml (20°C) in water
| MeltingPt = >175-176°C (448-449 K)
| BoilingPt = 219°C (492 K)
| pKa = 8.1
}}
| Section7 = {{Chembox Hazards
| ExternalMSDS = [http://www.jtbaker.com/msds/englishhtml/T7111.htm External MSDS]
| MainHazards = Irritant
| NFPA-H = 2
| NFPA-F =
| NFPA-R =
| FlashPt = Non-flammable
| RPhrases = {{R36}}, {{R37}}, {{R38}}.
| SPhrases = {{S26}}, {{S36}}.
}}
}}
{{this|the chemical compound}}
'''Tris''' is an abbreviation of the [[organic compound]] known as tris(hydroxymethyl)aminomethane, with the formula (HOCH<sub>2</sub>)<sub>3</sub>CNH<sub>2</sub>. Tris is extensively used in [[biochemistry]] and [[molecular biology]].<ref>Gomori, G., Preparation of Buffers for Use in Enzyme Studies. Methods Enzymology., 1, 138-146 (1955).</ref> In [[biochemistry]], tris is widely used as a component of [[buffer solution]]s, such as in [[TAE buffer|TAE]] and [[TBE buffer]], especially for solutions of [[nucleic acid]]s. It is a [[primary amine]] and thus undergoes the reactions associated with typical amines, e.g. condensations with aldehydes.
==Buffering features==
Tris has a [[pKa]] of 8.06, which implies that the buffer has an effective [[pH]] range between 7.0 and 9.2.
===Buffer details===
* The pK<sub>a</sub> declines approximately 0.03 units per degree Celsius rise in temperature.
* Silver-containing single-junction pH electrodes are incompatible with Tris (Ag-Tris precipitation clogs the junction). Double-junction electrodes are resistant to this problem, and non-silver containing electrodes are immune.
* It is toxic to mammalian cells.
* A common variant of tris (aka tris base) is tris-HCl, the acid salt. When titrated to a specific pH with the corresponding counter ion (OH- for tris-HCl, H+ for tris base) they are equivalent. However, the molecular weights are different and must be correctly accounted for in order to arrive at the expected buffer strength.
==Preparation==
Tris is prepared in two steps from [[nitromethane]] via the intermediate (HOCH<sub>2</sub>)<sub>3</sub>CNO<sub>2</sub> . Reduction of the latter gives tris(hydroxymethyl)aminomethane.<ref>Sheldon B. Markofsky “Nitro Compounds, Aliphatic” Ullmann's Encyclopedia of Industrial Chemistry 2002 by Wiley-VCH, Wienheim, 2002. DOI: 10.1002/14356007.a17_401.</ref>
==Uses==
The useful buffer range for Tris (7-9) coincides with the typical physiological pH of most living things. This, and its low cost, make Tris one of the most common buffer elements in use in the biology/biochemistry lab.
==References==
<references/>
[[Category:Alcohols]]
[[Category:Amines]]
[[Category:Buffers]]
[[de:TRIS]]
[[fr:Tris]]
[[ja:トリスヒドロキシメチルアミノメタン]]
[[pt:Tris]]
[[zh:三羟甲基氨基甲烷]]