Talk:Haematoxylin

Toxic?
Is this toxic?

Thanks, Wanderer57 (talk) 12:46, 12 June 2011 (UTC)
 * The name is derived from it's source, Haematoxylum campechianum, not from the word toxin. -- Ed (Edgar181) 23:52, 4 August 2016 (UTC)

Spelling
As this page uses mostly British spelling, not UK (haem..., aluminium), I have changed 'colo(u)r...' and '...ogic(al)' to British spelling as well. PhilUK (talk) 21:40, 22 August 2011 (UTC)

Hematoxylin is a basic and positively charged compound
Who likes to show me the positive charge? ;) --FK1954 (talk) 20:51, 4 August 2016 (UTC)
 * That claim is clearly incorrect, so I have removed it. -- Ed (Edgar181) 23:51, 4 August 2016 (UTC)
 * Thanks a lot! --FK1954 (talk) 18:49, 7 August 2016 (UTC)

History
The material used for dying was very frequently called "logwood liquor," according to a number of late 19th c. dying sources, such as the Practical Ostrich Feather Dyer, by Alexander Paul (Philadelphia, 1888). — Preceding unsigned comment added by Hilokid (talk • contribs) 16:17, 25 May 2017 (UTC)

References vs. notes
I have added some references, and would like to add more. I now see that my inline citations are under notes, not references. I'm not sure how to reconcile that, but I will look at help pages and try to figure it out. --Waughd (talk) 23:42, 15 March 2019 (UTC)
 * thank you for fixing that Waughd (talk) 23:15, 18 March 2019 (UTC)

Removed a section on bluing Comment
I removed a section on bluing that seemed redundant and maybe overly specific.

The text removed is below.

''When tap water is not sufficiently alkaline, or is even acidic and is unsatisfactory for blueing haematoxylin, a tap water substitute consisting of 3.5 g NaHCO3 and 20 g MgSO4·7H2O in one litre of water with thymol (to inhibit formation of moulds), is used to accelerate blueing of thin paraffin sections. Addition of a trace of any alkali to tap or distilled water also provides an effective blueing solution; a few drops of strong ammonium hydroxide or of saturated aqueous lithium carbonate, added immediately before use, are sufficient for a 400 ml staining dish full of water. Use of very cold water slows down the blueing process, whereas warming accelerates it. In fact, the use of water below 10 °C for blueing sections may even produce pink artifact discolorations in the tissue.''

The paragraph above the one removed covers the fact that bluing can be accomplished with hard water or the addition of ammonium hydroxide to water. I think the recipe given is correct (although I didn't look it up yet) and I think it is referring to what is know as Scott's tap water substitute, so I'm not disagreeing with the content by any means.

Waughd (talk) 23:27, 18 March 2019 (UTC)

Removed unsupported sentence on price increases.
I removed this sentence. (below) "Before the use of any alternatives became firmly established, haematoxylin returned to the market, though at a higher price, and resumed its place in histopathology."

There is no reference, for this, at least the higher cost part. For all my reading on the topic, I have not seen reference to increased costs; and although I think it's very possible prices did increase, I just can find enough support to state that. Waughd (talk) 22:48, 28 March 2019 (UTC)

Removed section
I removed the following section from the page. I feel the first paragraph has been mostly covered in the rest of the text, and the 2nd paragraph has no citations. It would be nice to eventually include a section on the formation of lakes and chemical action of the dye, but I don't think this removed text is adding anything meaningful at this point.

Removed text
 * Aluminium solutions
 * The three main alum haematoxylin solutions employed are Ehrlich's haematoxylin, Harris's haematoxylin, and Mayer's haematoxylin. The name haemalum is preferable to "haematoxylin" for these solutions because haematein, a product of oxidation of haematoxylin, is the compound that combines with aluminium ions to form the active dye-metal complex. Alum haematoxylin solutions impart to the nuclei of cells a light transparent red stain that rapidly turns blue on exposure to any neutral or alkaline liquid.


 * Alum or potassium aluminium sulfate used as the mordant usually dissociates in an alkaline solution, combining with OH− of water to form insoluble aluminium hydroxide. In the presence of excess acid, aluminium hydroxide cannot be formed, thus causing failure of aluminium haematoxylin dye-lake to form, due to lack of OH− ions. Hence, acid solutions of alum haematoxylin become red. During staining, alum haematoxylin-stained sections are usually passed on to a neutral or alkaline solution (e.g., hard tap water or 1% ammonium hydroxide) in order to neutralize the acid and form an insoluble blue aluminium haematin complex. This procedure is known as blueing.

End of removed text

Waughd (talk) 19:38, 26 May 2019 (UTC)