tag:blogger.com,1999:blog-32079676.post3337925111419826766..comments2024-02-13T21:22:02.522-08:00Comments on RRResearch: Making the hemin stock/solving a chemical puzzleRosie Redfieldhttp://www.blogger.com/profile/06807912674127645263noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-32079676.post-74637940573374419902024-02-12T12:25:21.081-08:002024-02-12T12:25:21.081-08:00For a long time now I've used a 1N solution of...For a long time now I've used a 1N solution of NaOH to make hemin stocks for anaerobic culture media (5 to 10 mg/ml). I filter sterilize with 0.22 micron PES membrane filter and store it refrigerated in the dark for up to 6 months. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32079676.post-7488469136424558822019-08-14T10:33:04.213-07:002019-08-14T10:33:04.213-07:00IANAC (I am not a chemist) but I doubt it.IANAC (I am not a chemist) but I doubt it.Rosie Redfieldhttps://www.blogger.com/profile/06807912674127645263noreply@blogger.comtag:blogger.com,1999:blog-32079676.post-89272778067674862462019-08-14T01:35:44.211-07:002019-08-14T01:35:44.211-07:00Is there any solid lipid that can dissolve hemin?Is there any solid lipid that can dissolve hemin?Anonymoushttps://www.blogger.com/profile/07712535977969094713noreply@blogger.comtag:blogger.com,1999:blog-32079676.post-58720249825267500522016-03-29T06:07:00.501-07:002016-03-29T06:07:00.501-07:00In the fridge, in a glass bottle. It keeps for ye...In the fridge, in a glass bottle. It keeps for years.Rosie Redfieldhttps://www.blogger.com/profile/06807912674127645263noreply@blogger.comtag:blogger.com,1999:blog-32079676.post-52039672688896002422016-03-29T06:05:35.871-07:002016-03-29T06:05:35.871-07:00how do you store the stock solution and for how lo...how do you store the stock solution and for how long?<br />Sam.Alhttps://www.blogger.com/profile/09173502917095630267noreply@blogger.comtag:blogger.com,1999:blog-32079676.post-21419507344523130222015-06-11T13:16:56.803-07:002015-06-11T13:16:56.803-07:00What is the maximum solubility in DMSO?What is the maximum solubility in DMSO?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32079676.post-71926463428166946142013-08-03T13:50:31.479-07:002013-08-03T13:50:31.479-07:00Rosie, this is something I'll have to look int...Rosie, this is something I'll have to look into in more detail next time I use it. So far, I've just been following received protocols with respect to Hemin.<br /><br />One important issue is that we are just using it as a delivery vehicle for iron. The hemin itself is not necessary for Xylella (I had forgotten that it was "factor X" for Haemophilus). We always autoclave it once it is mixed with the main medium. Our stock solution is stable (for our purposes) for over a month at 4 degrees... but I've never looked into the details of its behavior.Adam Retchlesshttps://www.blogger.com/profile/10276008143626244411noreply@blogger.comtag:blogger.com,1999:blog-32079676.post-6882670792912082692013-08-02T19:21:51.533-07:002013-08-02T19:21:51.533-07:00IANAChemist, but it seems pretty clear to me. Hemi...IANAChemist, but it seems pretty clear to me. Hemin contains two carboxylic acid groups. At low pH, these will be protonated, and thus uncharged. Large uncharged organic molecules aren't usually very water soluble.<br /><br />At high pH, those groups will deprotonate, giving the molecule a charge of -2. That will dramatically increase water solubility. That's consistent with Adam's report of simply using dilute NaOH.<br /><br />Triethanolamine is also basic, due to the tertiary amine, so adding TEA to the water should have the same effect. TEA-HCl, the conjugate acid, would not raise the pH, but adjusting the pH to 8.0 would do the trick.<br /><br />I'm not chemically savvy enough to comment on the possibility that TEA helps due to surfactant activity, but my money is on the simple pH effect. (I do seem to recall that TEA may have mild antimicrobial properties, though, so that might be a reason to use it over NaOH.)qetzalnoreply@blogger.comtag:blogger.com,1999:blog-32079676.post-11747084748563991382013-08-02T01:37:33.600-07:002013-08-02T01:37:33.600-07:00We use DMSO (dimethylsulfoxide). Filter-sterilise ...We use DMSO (dimethylsulfoxide). Filter-sterilise through a 0.2um nylon membrane, store frozen at -20C in small or single-use aliquots. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-32079676.post-65543033452904396332013-08-01T23:55:54.153-07:002013-08-01T23:55:54.153-07:00Huh! How do you sterilize it? How do you store i...Huh! How do you sterilize it? How do you store it? How long is it stable for?Rosie Redfieldhttps://www.blogger.com/profile/06807912674127645263noreply@blogger.comtag:blogger.com,1999:blog-32079676.post-37601520360087651082013-07-31T22:40:56.433-07:002013-07-31T22:40:56.433-07:00For Xylella fastidiosa, we dissolve Hemin Chloride...For Xylella fastidiosa, we dissolve Hemin Chloride in 0.05N NaOH. Now you've got me wondering what the difference is between using NaOH and using triethanolamine pH8.Adam Retchlesshttps://www.blogger.com/profile/10276008143626244411noreply@blogger.com