|WikiProject Microbiology||(Rated B-class, Top-importance)|
Right now the introducing definition is "Gram-negative bacteria are those bacteria that do not retain crystal violet dye in the Gram staining protocol.",  refering to an article that states nothing about the definition. This sound like a strange definition and if this really is the true definition, it should be clearly stated why they are coloured in contrast to gram-positive bacteria. Does anyone have a reliable source on what definition we should go for? 18.104.22.168 (talk) 20:53, 22 September 2010 (UTC) This is covered at http://www.horizonpress.com/gateway/gram-negative-bacteria.html as follows: In microbiology, the visualization of bacteria at the microscopic level is facilitated by the use of stains, which react with components present in some cells but not others. This technique is used to classify bacteria as either Gram-positive or Gram-negative depending on their colour following a specific staining procedure originally developed by Hans Christian Gram. Gram-positive bacteria appear dark blue or violet due to the crystal violet stain following the Gram stain procedure; Gram-negative bacteria, which cannot retain the crystal violet stain, appear red or pink due to the counterstain (usually safranin). The reason bacteria are either Gram-positive or Gram-negative is due to the structure of their cell envelope. (The cell envelope is defined as the cell membrane and cell wall plus an outer membrane, if one is present.) Gram-positive bacteria, for example, retain the crystal violet due to the amount of peptidoglycan in the cell wall. It can be said therefore that the Gram-stain procedure separates bacteria into two broad categories based on structural differences in the cell envelope. — Preceding unsigned comment added by 22.214.171.124 (talk) 15:27, 13 July 2012 (UTC)
The introduction is too jargon-y and needs to have more of an eye on its audience. Why do most people come to the Gram-negative bacteria page? I can't say for sure, but I'd bet they're looking for information about the relationship between this bit of information and real-world application, most notably in the context of antibiotics.
The details are important, but they're meaningless without context. As in, "how does this fit outside of the academic systemization of everything?" — Preceding unsigned comment added by 126.96.36.199 (talk) 14:59, 28 December 2013 (UTC)
- Agree. From yesterday's Telegraph: "The report pointed out that since 2000 only five new classes of antibiotic had been discovered and most were ineffective against one of the biggest threats, “gram negative” bacteria." This shows this issue is important, but our intro doesn't even hint at it. Someone who understands better than me should outline why this is all important in the real world. Thanks :) Malick78 (talk) 15:51, 8 July 2014 (UTC)
Standardized spelling & punctuation
Standard form used by the US Federal Government's Center for Disease Control is as follows: 
- Gram should be capitalized and never hyphenated when used as Gram stain; gram negative and gram positive should be lowercase and only hyphenated when used as a unit modifier.
- Gram staining
- gram negative
- gram-positive bacteria
- I lowercased gram-negative and gram-positive in their articles. Lowercasing is the style used by various medical dictionaries (e.g., Dorland's, M-W Medical, Taber's), AMA style, and others. As for whether the hyphen is treated as invariable across attributive and predicative positions, major styles such as AMA style treat them as permanent compounds, not temporary compounds, and thus hyphenate in both positions, because they are entered as headwords in medical dictionaries. The style in which the compound is styled openly in predicative position is treating the compound as a temporary compound, which is fine, but sometimes it comes simply from a resident editor who knows the general norm about temporary compounds (hyphenated attributive, open predicative) but is unaware of how the treatment of permanent compounds cascades over that. Quercus solaris (talk) 23:28, 11 June 2014 (UTC)
hey Quercus solaris On the face of it, it appears that this edit where you added "The adjectives gram-positive and gram-negative are conventionally lowercase in medical editing (as explained at Eponym > Capitalized versus lowercase.", is directed to people who might want to edit our article and change the capitalization. Is that true? If so, that makes sense, but they should be "invisible comments" as described here. If they are meant as part of the content, to inform readers about gram-negative bacteria themselves, then a) it needs to be somewhere in the body (nothing belongs in the lead that is not in the body, as per WP:LEAD) but b) I am not sure this is important enough to include in the article at all, much less in lead. Please clarify what the purpose of this is. Thanks. Jytdog (talk) 11:25, 11 June 2014 (UTC)
- Hi. It's meant to serve as part of readers' education generally. The person in mind is the science student who is learning about this topic and has a natural question about the way the word is written (why isn't it capitalized like eponyms usually are?). In that sense it's about education, not "mere how-to". Although I agree that it "doesn't matter" in the sense that it's irrelevant to the biology, it's relevant in that it answers a question that an observant student may well ask. I agree that it doesn't need to be in the lede. Someone who wants that answer can bother to look for it within the article body. I will move it down. Quercus solaris (talk) 14:44, 11 June 2014 (UTC)
- that may be OK, but you need a reliable source about how "gram negative" and "gram positive" are spelled in the real world. What wikipedia's guidelines are, is germane only to wikipedia editing. If you cannot supply a reliable source, we will need to delete this content. Jytdog (talk) 15:35, 11 June 2014 (UTC)
- btw, your pointing readers to Wikipedia's editing guideline is why I thought this might be a note for editors, as opposed to general content.Jytdog (talk) 15:39, 11 June 2014 (UTC)
- The link is not to Wikipedia's editing guidelines (which would be WP:MOS and its various sections). It is to the article on eponyms, in the section where it talks about how dictionaries style eponymous terms. Medical dictionaries (Dorland's, M-W Medical, Taber's, and others) style these adjectives lowercase (as they also do with parkinsonian, haversian, fallopian, and eustachian). I added citations. Quercus solaris (talk) 23:10, 11 June 2014 (UTC)
- I am with you now, thanks. I made the link to the eponyms article into a Wikilink, as the "see X" is still making me quesy with regard to Wikipedia:Manual of Style/Self-references to avoid. I hope you find the tweak acceptable. Thanks, I do think this is helpful, especially as an "Orthographic note" I love that header! You probably noticed that somebody else commented on the gram positive Talk page, approvingly. So thanks for this. Jytdog (talk) 00:22, 12 June 2014 (UTC)
Hey guys! I noticed that the external link here: Gram staining procedure and images was dead so I removed it. I'm not sure what it used to link to, but I just wanted to put a notice here in case someone more familiar with it wanted to put up a replacement. Ajpolino (talk) 02:55, 12 November 2015 (UTC)
This article's lead is confusing
Each of the lead's two paragraphs seems to be equally divided between overall introductory discussion of the class of bacteria (a good thing) and discussion of the staining process (a bad thing here). I accept that explaining what makes a bacterium gram-negative requires some mention of the staining method, but as it's currently written, the lead is way out of balance. It should be focused much more on the class of bacteria itself, and if details about alcohol washes and adding counterstains and correct timing are required in this article, then their proper place is further into the article's body.
Monoderm prokaryotes are indicated to be ancestral?
"Of these two structurally distinct groups of prokaryotic organisms, monoderm prokaryotes are indicated to be ancestral." This statement has 4 references, but all are from the same author. It is a bit biased. Modern phylogenic trees place the monoderm bacterial phyla between the diderm ones. See, for example, Terrabacteria. --Franciscosp2 (talk) 12:56, 8 October 2016 (UTC)