Talk:Mueller–Hinton agar

Error in article
The information in this article is almost certainly wrong. A knowledgeable person is has contact ed the Wikimedia pointing out the problem. We are in discussion about how best to address it, but I wanted to leave this note. At a minimum, the amount of beef infusion seems to be off by a factor of 100, but I haven't yet decided the best way to make a correction.-- S Philbrick (Talk)  15:42, 9 May 2016 (UTC)

For example, see this datasheet, which refers to 2 grams, rather than 300. As another example, see this site which refers to 2 grams, rather than 300.-- S Philbrick (Talk)  16:47, 9 May 2016 (UTC)


 * Hm. Good question. Unfortunately, the page cited isn't available on Google Books, but here's what I could find poking around:


 * Handbook of Microbiological Media (the current ref) - I can't see the cited page, however a couple pages later we get this recipe with 300g/L beef infusion (or 30% wt/vol). However, this is for "Mueller-Hinton medium with rabbit serum... for cultivation of Corynebacterium species". So maybe this is a specialized liquid media distinct from the classic solid Mueller-Hinton agar? Hard to tell...
 * This WHO guidebook on cultivating Salmonella gives a recipe for "Mueller Hinton II agar" with 2.0g/L beef extract (or 0.2%wt/vol). It is otherwise identical to the recipe in this article.
 * Sigma sells a Mueller-Hinton Agar with 4g/L (0.4%wt/vol) beef infusion solids. Other than that it's similar to our recipe here except it uses slightly less agar (15g/L rather than 17g/L).
 * Difco (now BD) has a recipe with a brief explanatory sheet as well. Looks like Mueller-Hinton Agar and Mueller-Hinton II Agar are different, but just barely. They also use 2g/L (0.2%wt/vol).
 * As far as I know, there is no authority on microbiology media recipes. Given that the current ref is the only one which shows this high amount of beef infusion, I'd go with the WHO guidebook and Difco. I'll poke around at work tomorrow and see if we have some reference books with common media recipes. I'll keep you posted. Ajpolino (talk) 04:16, 11 May 2016 (UTC)
 * Thanks for looking into this. Our rules regarding inquiries at OTRS I to keep the contents of emails confidential unless they provide permission. I haven't asked for permission so I'm not at liberty to disclose their email but there credentials suggest they know what they're talking about.


 * I did manage to find the page in Google books. Try this link, I think you will want the one on page 1248:


 * Google book link


 * It does seem to support the numbers although they data conversion from grams per liter to percent which I think is suspect. However, given that it wasn't a simple error of misreading the original source, we need enough additional sources with differing values to be able to reject the first source.


 * I see that you found some and I linked a couple in my note above. I don't think this is urgent but my hope is that you will check enough sources to persuade you of the right values and make the change. Thanks in advance.-- S Philbrick (Talk)  12:58, 11 May 2016 (UTC
 * Ok, so here is the text of Mueller and Hinton's paper originally describing Mueller-Hinton agar. For beef infusion, they call for 300mL of meat infusion made by boiling 1 pound of ground beef in 500mL water and straining (yeah, pretty old school right?). I assume this is where the number 300 came from.


 * As for the book (which gives 300g/L) it notes that the media is available as powder from BD and Oxoid Unipath. But BD uses 2g/L (Oxoid was bought out by Thermo. So Thermo sells Oxoid Mueller-Hinton agar now, but they don't have a recipe posted). So my guess based on the OTRS inquiry and the recipes available online, is that the correct amount is 2g/L (but that Sigma's 4g/L works just as well). I'm guessing the 300g/L is a typo introduced by mis-copying the original paper. That said, we are on somewhat shaky ground, since the book used as a source now would otherwise pass as a reputable source for this kind of thing. So if no one objects, I'll go ahead and change the article to 2g/L and we can all go back to our lives. If anyone thinks this is premature, feel free to revert my edit to the article and we'll talk about it more. I hope that's agreeable to all. Ajpolino (talk) 03:12, 13 May 2016 (UTC)
 * Sounds good. The mis-reading of the original recipe for the infusion recipe makes perfect sense. I don't think we are really that shaky. I'd be concerned if we had exactly one source and we were going to disagree with it but we have one source with a very plausible error and multiple sources which support a more reasonable number.-- S Philbrick (Talk)  11:08, 13 May 2016 (UTC)

Dead links
The WHO reference currently used in the article is a dead link. I have checked most of the talk page links and they are dead. Only the DIFCO pdf posted in the talk page sees to be a working link. However, it only works as a source for the ingredients. I found this while trying to find sources for a lab report and do not have time to fix it immediately. Sgeress (talk) 16:04, 21 October 2022 (UTC)