Tris

This article is about the chemical widely used as a biochemical buffer. For other uses, see Tris (disambiguation).

Tris

Names
Preferred IUPAC name

2-Amino-2-(hydroxymethyl)propane-1,3-diol

Other names

TRIS, Tris, Tris base, Tris buffer, Trizma, Trisamine, THAM, Tromethamine, Trometamol, Tromethane, Trisaminol

Identifiers

CAS Number

* 77-86-1 (free base) Y
* 1185-53-1 (hydrochloride) Y

3D model (JSmol)

* Interactive image

ChEBI |

* CHEBI:9754 Y

ChEMBL |

* ChEMBL1200391 N

ChemSpider |

* 6257 Y

IUPHAR/BPS

* 7328

KEGG |

* D00396 Y

PubChem CID

* 6503

RTECS number |

* TY2900000

UNII |

* 023C2WHX2V Y
* 383V75M34E (hydrochloride) Y

InChI

* InChI=1S/C4H11NO3/c5-4(1-6,2-7)3-8/h6-8H,1-3,5H2 Y

Key: LENZDBCJOHFCAS-UHFFFAOYSA-N Y

* InChI=1/C4H11NO3/c5-4(1-6,2-7)3-8/h6-8H,1-3,5H2

Key: LENZDBCJOHFCAS-UHFFFAOYAN

SMILES

* OCC(N)(CO)CO

Properties

Chemical formula

| C4H11NO3
Molar mass | 121.136 g·mol−1
Appearance  | White crystalline powder
Density | 1.328g/cm3
Melting point | >175-176 °C (448-449 K)
Boiling point |  219 °C (426 °F; 492 K)

Solubility in water

| ~50 g/100 mL (25 °C)
Acidity (pKa)  | 8.07 (conjugate acid)
Pharmacology

ATC code

| B05BB03 (WHO) B05XX02 (WHO)
Hazards
Main hazards | Irritant
Safety data sheet | External MSDS
R-phrases (outdated) | Template:R36 Template:R37 Template:R38
S-phrases (outdated) | S26 S36
NFPA 704 (fire diamond)  |

Flash point | Non-flammable

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

N verify (what is YN ?)
Infobox references

Tris, or tris(hydroxymethyl)aminomethane, or known during medical use as tromethamine or THAM, is an organic compound with the formula (HOCH2)3CNH2. It is extensively used in biochemistry and molecular biology as a component of buffer solutions[1] such as in TAE and TBE buffers, especially for solutions of nucleic acids. It contains a primary amine and thus undergoes the reactions associated with typical amines, e.g. condensations with aldehydes. Tris also complexes with metal ions in solution.[2] In medicine, tromethamine is occasionally used as a drug, given in intensive care for its properties as a buffer for the treatment of severe metabolic acidosis in specific circumstances.[3][4] Some medications are formulated as the "tromethamine salt" including hemabate (carboprost as trometamol salt), and "ketorolac trometamol".[5]

## Contents

* 1 Uses
* 1.1 Medical
* 2 Buffering features
* 2.1 Buffer details
* 2.2 Buffer inhibition
* 3 Preparation
* 4 See also
* 5 References

## Uses[edit | edit source]

The useful buffer range for tris (7–9) coincides with the physiological pH typical of most living organisms. This, and its low cost, make tris one of the most common buffers in the biology/biochemistry laboratory. Tris is also used as a primary standard to standardize acid solutions for chemical analysis.

Tris is used to increase permeability of cell membranes.[6] It is a component of the Moderna COVID-19 vaccine.[7]

### Medical[edit | edit source]

Tris (usually known as THAM in this context) is used as alternative to sodium bicarbonate in the treatment of metabolic acidosis.[8][9]

## Buffering features[edit | edit source]

The conjugate acid of tris has a pKa of 8.07 at 25 °C, which implies that the buffer has an effective pH range between 7.1 and 9.1 (pKa ± 1) at room temperature.

### Buffer details[edit | edit source]

* In general, as temperature decreases from 25 °C to 5 °C the pH of a tris buffer will increase an average of 0.03 units per degree. As temperature rises from 25 °C to 37 °C, the pH of a Tris buffer will decrease an average of 0.025 units per degree.[10]
* In general, a 10-fold increase in tris buffer concentration will lead to a 0.05 unit increase in pH and vice versa.[10]
* Silver-containing single-junction pH electrodes (e.g., silver chloride electrodes) are incompatible with tris since an Ag-tris precipitate forms which clogs the junction. Double-junction electrodes are resistant to this problem, and non-silver containing electrodes are immune.

### Buffer inhibition[edit | edit source]

* Tris inhibits a number of enzymes,[11][12] and therefore should be used with care when studying proteins.
* Tris can also inhibit enzyme activity via chelation of metal ions.[2]

## Preparation[edit | edit source]

Tris is prepared industrially by the exhaustive condensation of nitromethane with formaldehyde under basic conditions (i.e. repeated nitroaldol reactions) to produce the intermediate (HOCH2)3CNO2, which is subsequently hydrogenated to give the final product.[13]

## See also[edit | edit source]

* MOPS
* HEPES
* MES
* Common buffer compounds used in biology

## References[edit | edit source]

1. ↑ Gomori, G., Preparation of Buffers for Use in Enzyme Studies Archived 2011-07-26 at the Wayback Machine. Methods Enzymology., 1, 138-146 (1955).
2. ↑ 2.0 2.1 FISCHER, Beda E.; HARING, Ulrich K.; TRIBOLET, Roger; SIGEL, Helmut (1979). "Metal Ion/Buffer Interactions. Stability of Binary and Ternary Complexes Containing 2-Amino-2(hydroxymethyl)-1,3-propanediol (Tris) and Adenosine 5'-Triphosphate (ATP)". European Journal of Biochemistry. Wiley. 94 (2): 523–530. doi:10.1111/j.1432-1033.1979.tb12921.x. ISSN 0014-2956. PMID 428398.
3. ↑ Stanley, David; Tunnicliffe, William (June 2008). "Management of life-threatening asthma in adults". Continuing Education in Anaesthesia, Critical Care & Pain. 8 (3): 95–99. doi:10.1093/bjaceaccp/mkn012. Archived from the original on 11 May 2020. Retrieved 21 July 2017.
4. ↑ Hoste, Eric A.; Colpaert, Kirsten; Vanholder, Raymond C.; Lameire, Norbert H.; De Waele, Jan J.; Blot, Stijn I.; Colardyn, Francis A. (May 2005). "Sodium bicarbonate versus THAM in ICU patients with mild metabolic acidosis". Journal of Nephrology. 18 (3): 303–307. ISSN 1121-8428. PMID 16013019.
5. ↑ BNF 73 March-September 2017. British Medical Association,, Royal Pharmaceutical Society of Great Britain. London. 21 March 2017. ISBN 978-0857112767. OCLC 988086079.`{{cite book}}`: CS1 maint: others (link)
6. ↑ Irvin, R.T.; MacAlister, T.J.; Costerton, J.W. (1981). "Tris(hydroxymethyl)aminomethane Buffer Modification of Escherichia coli Outer Membrane Permeability". J. Bacteriol. 145 (3): 1397–1403. doi:10.1128/JB.145.3.1397-1403.1981. PMC 217144. PMID 7009585.
7. ↑ "Archive copy" (PDF). Archived (PDF) from the original on 2021-07-05. Retrieved 2021-07-06.`{{cite web}}`: CS1 maint: archived copy as title (link)
8. ↑ Kallet, RH; Jasmer RM; Luce JM; et al. (2000). "The treatment of acidosis in acute lung injury with tris-hydroxymethyl aminomethane (THAM)". American Journal of Respiratory and Critical Care Medicine. 161 (4): 1149–1153. doi:10.1164/ajrccm.161.4.9906031. PMID 10764304.
9. ↑ Hoste, EA; Colpaert, K; Vanholder, RC; Lameire, NH; De Waele, JJ; Blot, SI; Colardyn, FA (2005). "Sodium bicarbonate versus THAM in ICU patients with mild metabolic acidosis". Journal of Nephrology. 18 (3): 303–7. PMID 16013019.
10. ↑ 10.0 10.1 "Sigma tris(hydroxymethyl)aminomethane; Tris Technical Bulletin No. 106B" (PDF). Sigma-Aldrich. Archived (PDF) from the original on 2020-11-30. Retrieved 2020-06-04.
11. ↑ Desmarais, WT; et al. (2002). "The 1.20 Å resolution crystal structure of the aminopeptidase from Aeromonas proteolytica complexed with Tris: A tale of buffer inhibition". Structure. 10 (8): 1063–1072. doi:10.1016/S0969-2126(02)00810-9. PMID 12176384.
12. ↑ Ghalanbor, Z; et al. (2008). "Binding of Tris to Bacillus licheniformis alpha-amylase can affect its starch hydrolysis activity". Protein Pept. Lett. 15 (2): 212–214. doi:10.2174/092986608783489616. PMID 18289113.
13. ↑ Markofsky, Sheldon, B. (15 October 2011). "Nitro Compounds, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Vol. 24\. p. 296\. doi:10.1002/14356007.a17_401.pub2. ISBN 978-3527306732. `{{cite book}}`: Missing or empty `|title=` (help)

*[CID]: Compound ID
*[S26]: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice
*[S36]: Wear suitable protective clothing