[3dem] [EXTERNAL] Uranyl acetate alternative

Thu Oct 21 02:15:33 PDT 2021

In 35 years of negative staining my go to stain is sodium silicotungstate. It provides good contrast has a fine grain, and therefore reveals details not obvious with uranyl salts and is great for really small molecules, it has none of the problems of radioactivity for handling and disposal. I use it with all the conventional buffers including PBS, but it's of no use when detergent is present.
UK suppliers sell the acid form (not sure about anywhere else), and to achieve the best affects you need to neutralise your solution. I prefer to prepare a batch of the salt from the acid solution and precipitate it out to keep the solid for later use ... it keeps for years that way. I then prepare a 1% solution of the salt form, which also keeps for many months.
If anyone would like the recipe for the conversion to the salt form, I'd be happy to supply it.

Lesley Calder

The Francis Crick Institute

1 Midland Road

London NW1 1AT

________________________________
From: 3dem <3dem-bounces at ncmir.ucsd.edu> on behalf of Riedel, Dietmar <driedel at gwdg.de>
Sent: 20 October 2021 14:32
To: Sharon G Wolf <Sharon.Wolf at weizmann.ac.il>
Cc: 3dem at ncmir.ucsd.edu <3dem at ncmir.ucsd.edu>
Subject: Re: [3dem] [EXTERNAL] Uranyl acetate alternative

External Sender: Use caution.

I use NanoVan or NanoW. NanoVan is great for negativ stain if phosphates omit the use of Uran stains. But it is a vanadium stain and therefore much weaker than Uran salt. I keep it in the fridge for years.
Dietmar

Mobil gesendet

Am 20.10.2021 um 15:07 schrieb Sharon G Wolf <Sharon.Wolf at weizmann.ac.il>:

I have used sodium silicotungstate on a variety of samples.  Also phosphotungstic acid is a classic.

Also, like Zuben, I have used ammonium molybdate and methylamine tungstate.   Both need to be made fresh. They can’t sit on the shelf for a long time like UAc can.
None of them has as much contrast as UAc, except for the sodium silicotungstate, which can be outstanding. But it can cause some complexes to fall apart.

Sharon

From: 3dem <3dem-bounces at ncmir.ucsd.edu> On Behalf Of Brown, Zuben
Sent: Wednesday, 20 October, 2021 15:41
To: Denis Chrétien <denis.chretien at univ-rennes1.fr>; 3dem at ncmir.ucsd.edu
Subject: Re: [3dem] [EXTERNAL] Uranyl acetate alternative

Hi Denis,

I've tried ammonium molybdate and methylamine tungstate with acceptable results on different membrane proteins.

Obviously, the contrast is reduced compared to uranyl acetate but the management of the waste materials is greatly simplified.

best wishes,

Zuben

________________________________

From: 3dem <3dem-bounces at ncmir.ucsd.edu<mailto:3dem-bounces at ncmir.ucsd.edu>> on behalf of Denis Chrétien <denis.chretien at univ-rennes1.fr<mailto:denis.chretien at univ-rennes1.fr>>
Sent: Wednesday, October 20, 2021 3:35 AM
To: 3dem at ncmir.ucsd.edu<mailto:3dem at ncmir.ucsd.edu> <3dem at ncmir.ucsd.edu<mailto:3dem at ncmir.ucsd.edu>>
Subject: [EXTERNAL] [3dem] Uranyl acetate alternative

Dear all,

It becomes difficult to posses Uranyl Acetate salts. Hence we would like to have your feedback concerning alternatives for sections and negative staining. Along this line, we would appreciate your experience concerning this salt :

https://urldefense.proofpoint.com/v2/url?u=https-3A__www.tedpella.com_SDS-5Fhtml_19485-5Fsds.pdf&d=DwIGaQ&c=-35OiAkTchMrZOngvJPOeA&r=L7-zyQ-04fFCMRqzLIOnx7H0exGZHwIQe_wMPuY600I&m=J6SGoWLqZ81NUd74AhpGSKJazdPjFRhsG3xONcgDMBs&s=v05ry6aOJWEUCAIB4brZ3XFDRLRVpsWtgx52k9Ojiiw&e= <https://urldefense.proofpoint.com/v2/url?u=https-3A__eur03.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furldefense.proofpoint.com-252Fv2-252Furl-253Fu-253Dhttps-2D3A-5F-5Fwww.tedpella.com-5FSDS-2D5Fhtml-5F19485-2D5Fsds.pdf-2526d-253DDwMFaQ-2526c-253D-2D35OiAkTchMrZOngvJPOeA-2526r-253DL7-2DzyQ-2D04fFCMRqzLIOnx7H0exGZHwIQe-5FwMPuY600I-2526m-253DhRDyTdJW4hH05tkZJrE0XkfrezWAxeD53hmQWoZC2pk-2526s-253DSzdIxK-5F0wo-2D0i8bTfRNyPQnZX2l3AyLDYJwGNuZsMTs-2526e-253D-26data-3D04-257C01-257C-257C12340787eb834303351c08d993ce1012-257C4eed7807ebad415aa7a99170947f4eae-257C0-257C1-257C637703335522542045-257CUnknown-257CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0-253D-257C3000-26sdata-3DDKY3YP02zGwZ2rmB7iTw5Ak-252Frg-252BfXZg-252FwaCWZx4LZ40-253D-26reserved-3D0&d=DwIGaQ&c=-35OiAkTchMrZOngvJPOeA&r=L7-zyQ-04fFCMRqzLIOnx7H0exGZHwIQe_wMPuY600I&m=J6SGoWLqZ81NUd74AhpGSKJazdPjFRhsG3xONcgDMBs&s=J9bsJvBcqZ_-NCCpZmjpO7VLh_ZkCV6FZKz7L28CcjI&e= >

Other suggestions are welcomed!

Best,

Denis

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Tel. +33 (0)2 23 23 67 64
https://urldefense.proofpoint.com/v2/url?u=https-3A__igdr.univ-2Drennes1.fr_&d=DwIGaQ&c=-35OiAkTchMrZOngvJPOeA&r=L7-zyQ-04fFCMRqzLIOnx7H0exGZHwIQe_wMPuY600I&m=J6SGoWLqZ81NUd74AhpGSKJazdPjFRhsG3xONcgDMBs&s=X27ZKnO9L8UO9XfHNvkRHurFXk36gKYpju075aMZSiU&e= <https://urldefense.proofpoint.com/v2/url?u=https-3A__eur03.safelinks.protection.outlook.com_-3Furl-3Dhttps-253A-252F-252Furldefense.proofpoint.com-252Fv2-252Furl-253Fu-253Dhttps-2D3A-5F-5Figdr.univ-2D2Drennes1.fr-5F-2526d-253DDwMFaQ-2526c-253D-2D35OiAkTchMrZOngvJPOeA-2526r-253DL7-2DzyQ-2D04fFCMRqzLIOnx7H0exGZHwIQe-5FwMPuY600I-2526m-253DhRDyTdJW4hH05tkZJrE0XkfrezWAxeD53hmQWoZC2pk-2526s-253DJ9NRrJh9gl0QKmDtkcBNTdu6xKGp5rtgq6N8Gs-2DjWos-2526e-253D-26data-3D04-257C01-257C-257C12340787eb834303351c08d993ce1012-257C4eed7807ebad415aa7a99170947f4eae-257C0-257C1-257C637703335522547021-257CUnknown-257CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0-253D-257C3000-26sdata-3Diwz8EcXYQpO8hOqI0xfC1tM-252BLPs5i9ieU3vNKD3RAzQ-253D-26reserved-3D0&d=DwIGaQ&c=-35OiAkTchMrZOngvJPOeA&r=L7-zyQ-04fFCMRqzLIOnx7H0exGZHwIQe_wMPuY600I&m=J6SGoWLqZ81NUd74AhpGSKJazdPjFRhsG3xONcgDMBs&s=6IMD2frEd54ZTVw2wwbuQ2_Je3_2HNWnYbi1cHDsrQY&e= >
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