Tris

From Wikipedia, the free encyclopedia

Tris

General
Systematic name	2-Amino-2-(hydroxymethyl)propane-1,3-diol
Other names	TRIS, Tris, Tris base, Tris buffer, Trizma(TM), Trisamine, THAM, Tromethamine, Trometamol, Tromethane
Molecular formula	C₄H₁₁NO₃
SMILES	C(C(CO)(CO)N)O
Molar mass	121.135 g/mol
Appearance	White crystalline powder
CAS number	[77-86-1]
Properties
Density and phase	? g/l, solid (25°C)
Solubility in water	67 g/100 ml (20°C)
Melting point	>170°C (443 K)
Boiling point	219°C (492 K)
Acidity (pK_a)	8.3
Hazards
MSDS	External MSDS
Main hazards	Irritant
NFPA 704	0 2 0
Flash point	Non-flammable
R/S statement	R: R36, R37, R38. S: S26, S36.
RTECS number	TY2900000
Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references

This article is about the chemical compound. For other uses, see Tris (disambiguation).

Tris is an abbreviation of the trivial name (trishydroxymethylaminomethane) for 2-amino-2-hydroxymethyl-1,3-propanediol. It is widely used as a component of buffer solutions, such as in TAE and TBE buffers used in biochemistry, with an effective pH range between 6.5 and 9.7. Tris has labile protons with a pKa of 8.30 (at 20 °C; this declines approximately 0.03 units per degree Celsius rise in temperature). Tris is often used when working with nucleic acids. Tris is an effective buffer for slightly basic solutions, which keeps DNA deprotonated and soluble in water. EDTA binds to divalent cations, particularly magnesium (Mg2+). These ions are necessary co-factors for many enzymes; Magnesium is a co-factor for many DNA-modifying enzymes.

Tris is toxic to mammalian cells, and reacts strongly with pH electrodes. It can react with primary amines.

[edit] Uses

Tris is used as an intermediate for the preparation of surface active agents, vulcanization accelerators, and pharmaceuticals, and used as a titrimetric standard.