Dear all, since I guess this post fits in here too, I would like to point to perhaps another possibility:

non-isotopic (4%) Hafnium chloride in (100%) Methanol used as a contrasting/staing solution for ultrathin sections (SPURRS, 60/80 nm thickness):

(cf: http://onlinelibrary.wiley.com/doi/10.1002/jemt.20964/pdf or for the abstract see:

http://onlinelibrary.wiley.com/doi/10.1002/jemt.20964/abstract).

IKEDA et al, Microscopy Research and Technique Volume 74, Issue 9, pages 825–830, September 2011:

Keywords: nonisotope; hafnium chloride; uranyl acetate; ultrastructural contrast; fungus; plant

Abstract: This ultrastructural study showed that nonisotopic methanolic hafnium chloride and aqueous lead solution was an excellent new electron stain for enhancing TEM contrasts of fungal and plant cell structures. The ultrastructural definition provided by the new stain was often superior to that provided by conventional staining with uranyl acetate and lead. Definition of fine ultrastructure was also supported by quantitative data on TEM contrast ratios of organelles and components in fungal and plant cells. In particular, polysaccharides, which were localized in cell walls, glycogen particles, starch grains, and plant Golgi vesicle components, were much more reactive to the new stain than to the conventional one. The new nonisotopic stain is useful for enhancing the contrast of ultrastructure in biological tissues and is a safer alternative to uranyl acetate. Microsc. Res. Tech., 2011. © 2010 Wiley-Liss, Inc. This - I think - is really interesting to EM-ists....

Thanks also to Stefan to tell us that the Sm-Gd-triacetate-staining will be / is commercially available now. Best regards, Wolfgang

This is realy usefull and needed dear Michael Thanking you so much

Thanks Michael for this information. We will use the new staining soon and will report about our experience.

Thanks for this paper, we have already tried it and now switch to samrium instead of UA in routine protocols. Works both (en block and on grids) well.

Electron Microscopy Sciences just introduced a ready mixed Uranyl Acetate Replacement Stain based on samarium and gadolinium triacetate... just for your information.

Dear all, since I guess this post fits in here too, I would like to point to perhaps another possibility:

non-isotopic (4%) Hafnium chloride in (100%) Methanol used as a contrasting/staing solution for ultrathin sections (SPURRS, 60/80 nm thickness):

(cf: http://onlinelibrary.wiley.com/doi/10.1002/jemt.20964/pdf or for the abstract see:

http://onlinelibrary.wiley.com/doi/10.1002/jemt.20964/abstract).

IKEDA et al, Microscopy Research and Technique Volume 74, Issue 9, pages 825–830, September 2011:

Keywords: nonisotope; hafnium chloride; uranyl acetate; ultrastructural contrast; fungus; plant

Abstract: This ultrastructural study showed that nonisotopic methanolic hafnium chloride and aqueous lead solution was an excellent new electron stain for enhancing TEM contrasts of fungal and plant cell structures. The ultrastructural definition provided by the new stain was often superior to that provided by conventional staining with uranyl acetate and lead. Definition of fine ultrastructure was also supported by quantitative data on TEM contrast ratios of organelles and components in fungal and plant cells. In particular, polysaccharides, which were localized in cell walls, glycogen particles, starch grains, and plant Golgi vesicle components, were much more reactive to the new stain than to the conventional one. The new nonisotopic stain is useful for enhancing the contrast of ultrastructure in biological tissues and is a safer alternative to uranyl acetate. Microsc. Res. Tech., 2011. © 2010 Wiley-Liss, Inc. This - I think - is really interesting to EM-ists....

Thanks also to Stefan to tell us that the Sm-Gd-triacetate-staining will be / is commercially available now. Best regards, Wolfgang

Yaroslav Tsytsyura, as you are using this samarium salt and you seem happy about it, do you have protocoles to share? I am looking for a good protocole for either staining cells thin cuts and grids (for virus). In France, we can't order AU anymore since january... Thanks a lot if you (or anyone else)can provide me with this! Agnès

Agnès de Lacroix de Lavalette-Boehm:

Hi. We use samarium triacetate (ours is from Sigma http://www.sigmaaldrich.com/catalog/product/aldrich/325872?lang=de®ion=DE) for en block staining of cultured neurons: 2-3% in water, filtered through 0.2µm filter, incubation about 1 hour at RT after post-fixation with Osmium. The same 2-3% water solution is being used to post-stain the ultrathin sections on grids, time 20-30 min, RT, and then lead citrate. I tried to dissolve it in ethanol (similar as for uranyl acetate) - of course, it did not work. Tried to use the water solution also as the negative stain for bacteriophages, but did not succeed - had to use uranyl acetate either phosphotungstic acid. Maybe it was just a bad luck, I tried only once; in the original paper (see the topic for the link) they have used samarium also as the negative stain.

M.Hayat in his book describes also use of 3% ammonium molybdate (pH 5.6) for virus staining; never tried myself but maybe this could help you.

Good luck.

Yaroslav Tsytsyura,

thank you very much for helping! I'll try this and give you a feed back on our viruses (all kind but not on bacteriophages...) and sections.

I'lll keep in touch.

Have a god day!