Apologize for Lenghtiness....

Andrey, first of all I would like to point you to http://ibilabs.com/uranium-properties/, where you can find valuable information about http://europepmc.org/articles/PMC2106611/pdf/157.pdf .

But Uranyl Magnesium acetate is used also likely as a "postfixative" rather than a stain after e.g. FA-GA and /OR Osmium tetroxide fixation (" .... cells were then washed in SCB, postfixed with 2% (wt/vol) osmium tetroxide in SCB, stained with 0.5% aqueous magnesium uranyl acetate, dehydrated, .... " cf:

A High-Order Trans-Membrane Structural Linkage Is Responsible for Mitochondrial Genome Positioning and Segregation by Flagellar Basal Bodies in Trypanosomes by Ogbadoyi et al, Mol Biol Cell. 2003 May; 14(5): 1769–1779; pdf(504KB):

Article A High-Order Trans-Membrane Structural Linkage Is Responsibl...

= http_s://www.ncbi.nlm.nih.gov/pmc/articles/PMC165075/pdf/0141769.pdf

(when inserting the URL into yyour browser be sure to delete the underline character in between http and s:// see above!!]

Just only to let it be known to me and other interested colleagues:

how do you prepare / which Uranyl Magnesium acetate you are going to use?? Perhaps the following? one?:

Magnesium uranyl acetate*). Dissolve 100g of UO2(C2H3O2)2.2H2O in 60ml of glacial acetic acid and dilute to 500 ml. Dissolve 330g of Mg(C2H3O2)2.4H2O in 60ml of glacial acetic acid and dilute to 200 ml. Heat solutions to the boiling point until clear, pour the magnesium solution into time uranyl solution, cool and dilute to l liter. Let stand over night and filter if necessary.

It might be interesting to test whether a solution of Zinc uranyl acetate*) (usually reagent for sodium). might have improved (?) staining reaction for your task??: Preparation of Zinc uranyl acetate: Dissolve 10 of UO2(C2H3O2)2.2H2O in 6g of 30 % acetic acid with heat, if necessary, and dilute to 50 ml. Dissolve 30g of Zn(C2H3O2)2.2H2O in 3g of 30% acetic acid and dilute to 50 ml. Mix the two solutions, add 50 mg of NaCl, allow to stand over night and filter.

*)Source: https://saltlakemetals.com/reagentpreps/ = also or more/less the same as http://sites.chem.colostate.edu/diverdi/all_courses/CRC%20reference%20data/special%20analytical%20reagents.pdf

You might find it spectacular also to visit:

https://wikivisually.com/wiki/Uranyl_acetate and have a look into:

Uranyl Magnesium Acetate - Reaction of Uranium - Lu Le Laboratory [2min 4K 16 likes https://www.youtube.com/watch?v=suQTl86R9Jk&feature=youtu.be

For sure you might end up with very similar results using only Uranyl acetate solution as your staining solution (it might depend on the type of solvent you are intending to use...which one?).

Principle: using the UO2Acetate stuff in the right manner and "care-fully" as usual [light shielded, and - if using 100%alcoholic(MetOH or EtOH), 1 ( to 4%) UO2ac-solutn - protected from possible evaporation, staining in the dark, absolute cleaness and correct handling]

Interesting question! Would love to hear/read more about then....

Best wishes and regards,

Wolfgang

NB: Apologies: edited for marginal spelling errors some minute after initial posting

Hi,

I cannot answer your question. However, if you intend to have good contrast in ultrathin sections, you could perhaps follow the approach described in the article "Improvend contrast by a simplified post-staining procedure for ultrathin sections of resin-embedded bacterial cells: Application of ruthenium red" Jan. 1995 Journal of Basic Microbiology 35(5): 349-355 B.Vogt, R.Berker, F.Mayer DOI . 10.1002/jobm.3620350510

Here is an abstract:

High contrast can be obtained in ultrathin sections of bacterial cells embedded in the low-temperature resin Lowicryl by post-staining of the sections on an aqueous ruthenium-red solution. Post-staining with lead citrate can be omitted. Combination with post-staining with uranyl acetate results in further improvement of contrast (cytoplasmic membrane, membranes in general, nucleoid, envelope of inclusion bodies, polyphosphate and, in the case of bacteria, intracellular defective bacteriophages, wall layers, slime and capsule. The procedure is also suited for post-staining for immunocytochemical analyses.

I have tried ruthenium red on routine cell cultures, did not find an improvement.

Neither I.... but most obviously I did something wrong when trying to use RuRed in the 80-90ies for use as promising standard staining for ultrathin resin (EPON 812, EPOnate) sections of cartilage. ...

Well, if you have better camera, you would not needed to stain the sections. I have Gatan US, I wont stain sections, post fixation with OsO4 and US at 70% alcohol dehydration step works well with my scope.

Hi Dr.Muss,

as I mentioned, our resin was Lowicryl. Perhaps, this resin helps to protect - due to low temperature - presrvation of the "Biology" in the sample. This view seems to be supported by the fact that we found immunocytochemical approaches with Lowicryl much more effective than with samples embedded in other resins. After all, good preservation of the "Biology" in the resin-embedded sample might also be helpful for a contrast enhancement by ruthenium red. due to availablity of more sites for reaction with ruthenium red. Your view?

Apologies again for lengthiness....

Dear Dr. Mayer, just found your reply and your request for 'my view'. Thank you for your statement. The truth is that I (for several reasons I won't devulge here) had no long - or better routine - practical experience with Lowicryl (i.e. use for diagnostic purposes; except two or three series of preparing and processing specimens into Lowicryls K4M and HM20, when testing a self made PLT(as you for sure know: Progressive Lowering Temperature) -apparatus with an in-built polymerization unit to be used with processing temps down to/@ -35/-40°C ). Naturally I was interested in all those techniques used in the then upcoming immunohistochemistry & immunocytochemistry issues during mid and late 80ies into the 90ies... and not only have read a lot of articles... Therefore I know also that RuRed not only was used as a section post-staining technique BUT also was used as a 'primary' fixative*) - esp. in conjunction with OsO4 - unfortunately I have not found the article you mentioned above in my e-digital library (which hosts approx. 10,000 -12,000 more/ less specific articles concerning techniques, methods, diagnostic matters in (SEM too) TEM. So it would be helpful to be able to read your paper VOGT et al 1995 for a 'late evaluation....' would you mind to provide an e-reprint (pdf)? If yes, I thank you in advance....

*) e.g. for previously pelleted cells containing / with intracellular polyaccharides a primary incubation in ~0.1-02% RuRed (in an appropriate buffer, e.g. Na-cacodylate, or even a zwitterionic buffer like HEPES) for an hour or so, after apropriate washing the usual GA (aldehyde) fixation followed (containing also RuRed @0.1-0.2%) and after that followed by a mixture of 1%OsO4-0.1-0.2% RuRed, washing, dehydration a susual, embedding into resin...).An interesting paper using the method of Luft, 1971 also was used in 1995 by KRUTH et al (Sequestration of Acetylated LDL and Cholesterol Crystals by Human Monocyte-Derived Macrophages) cf: PMC @ http_s://www.ncbi.nlm.nih.gov/pubmed/7698980 (NB: in the former URL-link prior to pasting into youer browser delete the >underline-sign in between "http" and "s://") which can be found also at: https://pdfs.semanticscholar.org/5336/6295132d5ac311b0161c9e88ee7cdb55076c.pdf or on ResearchGate: Article Sequestration of acetylated LDL and cholesterol crystals by ...

• Source
• PubMed , otherwise only a tip for receiving "FULL TEXT by REQUEST":

Quote: " Do you want to read the full-text of this article?

Life sciences researchers are likely to respond – send a request to ask the authors for the full-text version of it." (End of quote).

Interestingly, there have been reports about a kind of more / less a specific action of RuRed with respect to Ca2+binding sites which also bind ruthenium red...so it might be that in such binding there also an improvement in "staining" intracellular/extracellular "biological" structures might be anticipated....who knows about the whole potential of all these more/less sophisticated "heavy metal" dyes (RuRed as "tracer".... like the (colloidal) Lanthanum nitrate additive to primary fixation I used often in my early years of profession...).

Thank you very much for your "view".! Too bad that I do not have a reprint of my article. I could try to organize one. If I get one, you will immediately receive it. By the way: I retired 14 years ago, I had no longer any direct access to scientific libraries etc., and I moved several times after retirement.

Kind regards,

Frank Mayer

Dear Dr. Mayer, so you are a bit longer in this state of "scientific uneasiness".... yes, I understand ..." I had no longer any direct access to scientific libraries etc., " as this happened to me too (but fortunately had left some really collegial relations to some librarians at the University Libraries here in Salzburg....and do write to Editorial offices of Journals when necessary asking for their help....not always effective or successful but - at least - helpful....IF it is possible to retrieve your the article from the digital edition of the Journal I thank you so much for your courtesy to provide me with a pdf.......For now, again my sincere thanks, best regards, Wolfgang