Talk:Tris

Molecular weight

the MW of tris is 121.14 g/mole, the MW of tris-HCl is 157.59 http://www.jtbaker.com/msds/englishhtml/t7112.htm 129.3.17.129 (talk) 00:15, 22 June 2010 (UTC)

Solubility

The Solubility listed (220g/100mL) is not correct. This would make an 18.16M solution of Tris, which is definitely insoluble at RT (I just tried to make 5M @25C, heated it, sonicated it, stirred it overnight, really banged on it, and it was a no go. I was however able to make 2.5M Tris without much difficulty [at pH 8]). I think the solubility is somewhere closer to ~4M (somewhere in the neighborhood of 50g/100mL) but I can't seem to find information about saturated solutions of Tris in any of the CRC handbooks. Can someone more knowledgeable please correct this information, or baring that remove the solubility? —Preceding unsigned comment added by 137.131.130.41 (talk) 17:27, 11 August 2008 (UTC)

Could someone get the formulas on these document please it would really help out us students using the site for research

---I changed some of the information, which I found out wrong (source : Merck Index 13th edition). I don't know about the rest of the article.

I think that under the label "Buffering Features" talks too much about EDTA. —Preceding unsigned comment added by 157.92.44.74 (talk) 12:27, 16 January 2008 (UTC)

The article mentioned Tris being toxic to mammalian cells. Is there any citation to this claim? - X 129.78.64.101 (talk) 00:43, 20 February 2008 (UTC)

• I don't know if this counts as a good citation or not, but there was an April 1977 product notice issued by the CPSC stating that TRIS was to be banned as a flame retardant in children's clothing (http://www.cpsc.gov/cpscpub/prerel/prhtml77/77030.html) due to concerns over its possible carcinogenic qualities. Now, if this has been disproven since I'm not aware, but there was that concern there. 68.90.164.177 (talk) 16:43, 6 August 2008 (UTC)

Here is some safety data for Tris: http://msds.chem.ox.ac.uk/TR/tris%28hydroxymethyl%29aminomethane.html

But to give you an idea of how toxic that is, take a look at the same site's info on table salt (NaCl): http://msds.chem.ox.ac.uk/SO/sodium_chloride.html

It seems to be toxic in the same sense that many innocuous substances are. That is, if you ingest enough, they may be lethal. I think the toxicity to mammals claim should be removed.

Phillip SanMiguel (talk) 11:25, 6 October 2009 (UTC)

On the question of tris toxicity to mammalian cells, some confusion has arisen because there are two unrelated chemicals with the same nickname Tris. The present article is about tris-(hydroxymethly)-aminomethane, the biochemical buffer and therapeutic agent, which is at worst mildy toxic, as indicated by its MSDS. The other tris is the fire-retardant tris-(2,3,-dibromopropyl)-phosphate. The similarity in name only means that each molecule contains three of some group, the group named within the parentheses. The fire-retardant tris is not used in biochemistry and was indeed banned from use in children's clothing because of toxicity concerns. To help clear things up I have removed the sentence about toxicity of tris from this article and added the fire-retardant tris to the disambiguation page for tris.CharlesHBennett (talk) 03:50, 25 March 2010 (UTC) I have modified the introductory paragraph also, to make clear that there is another chemical nicknamed tris.CharlesHBennett (talk) 02:41, 9 October 2011 (UTC)

Infobox

If anyone ever wants to construct an infobox, here are the particulars. savidan^{(talk) (e@)} 09:02, 9 April 2006 (UTC)

(1) CAS No: 77-86-1; MF: (HOCH2)3CNH2; MW: 121.13624; BP(°C): 219-220(p=10 torr)

(2) Specification of Tris:

Appearance: white crystal

Content: ≥99.9%

Melting point: 168-171℃

Loss on drying: ≤0.5%

ASH: ≤0.05%

PH (0.1mol/L, 25℃):10.0-10.8

Insoluble in water: ≤0.03%

ABS (260nm): ≤0.2

Heavy metals: ≤5PPM

Fe: ≤5PPM

SO42+: ≤5PPM

Cl: ≤5PPM

Some of the analysis information you have here is only going to be specific to that lot. They aren't innate properties of tris itself. Benzene 15:10, 6 June 2006 (UTC)

Systematic name

The two alternative systematic names: 2-amino-2-hydroxymethyl-1,3-propanediol or 2-nitro-2-hydroxymethyl-1,3-propanediol describe quite different compounds. I would suggest that the latter (2-nitro) be deleted. Dr Thermo 15:23, 26 October 2007 (UTC)

Upper or lower case?

The upper and lower case of Tris/tris is not consistent. What is the correct case? —Preceding unsigned comment added by 137.248.208.240 (talk) 07:17, 13 October 2010 (UTC)

ISO uses capitalised Tris in all their standards that I have come across. 199.212.18.130 (talk) 15:47, 4 June 2019 (UTC)

Reference 6

It appears to be vandalized, I lack the technical skills to revert this to the original. 94.209.235.75 (talk) 16:01, 18 December 2010 (UTC)

 Fixed. Thanks for catching the error and reporting it here. -- Ed (Edgar181) 18:01, 18 December 2010 (UTC)

Criticism / drawback

Tris is by far the most popular buffer for molecular biology and biochemistry (for cell biology it is phosphate) so I think it would be fair to highlight some of its drawbacks. First of all a buffer with a pka above 8 is a poor choice for buffering at pH 7. Most people forget that. Additionally, Tris pka is much more temperature and concentration dependent than other buffers (and if the pka of the buffer changes the pH of the solution changes). Here's a link with some examples of changes in pH with change in temperature http://promega.wordpress.com/2011/02/25/what-makes-a-good-buffer/ And it's neutral at buffering pH so it is much more likely to transverse membranes. And that neutral primary amine is a good nucleophile as well. It is sterically hindered so less reactive than you would otherwise expect but it is a liability. And while Tris is cheap, so is MOPS and HEPES (which on the other hand decomposes when autoclaved).

Structurebiologist (talk) 20:22, 2 July 2013 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Tris/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

Under buffer details of the article, the use of 'counterion' is misleading. The counterion of Tris-HCl is the chloride ion. In solution the hydroxide ions and the hydronium ions change the acid/base properties of the water, and as a result the amine group can become charged or not charged. In fact when at low pH values the amine is positively charged. The concentration of hydroxide ions in a very basic solution may be in the vicinity 0.1 M; therefore, if I were to make a 0.4 M solution of Tris, there would not be enough 'counterions' to establish electronic neutrality (although the amine would not be charged at such a high pH).TEGCG (talk) 02:56, 21 October 2009 (UTC)

Last edited at 04:24, 21 October 2009 (UTC). Substituted at 09:16, 30 April 2016 (UTC)

Tris is not a Good's buffer

I removed references to Tris being one of Good's buffers from the article. Tris is not one of the 20 Good's buffers. Good's original 1966 paper used Tris as an example of a "bad" buffer in search for alternatives with better characteristics: "... some very inappropriate buffers have been used in biological research. These buffers have been bad because of inefficacy, undesired reactivity, or toxicity. '...' Tris(hydroxymethyl)aminomethane (Tris) has poor buffering capacity below pH 7.5. Moreover it is a primary aliphatic amine of considerable reactivity and consequently it is often inhibitory" (Quote from [1]https://doi.org/10.1021/bi00866a011). This has also been emphasised in other articles, e.g. [2]https://www.promega.de/en/resources/guides/lab-equipment-and-supplies/buffers-for-biochemical-reactions/; [3]https://doi.org/10.1021/acs.biochem.1c00200 and is also mentioned in the Good's buffer Wikipedia article (https://en.wikipedia.org/wiki/Good%27s_buffers). 128.176.164.101 (talk) 12:52, 5 April 2024 (UTC)