science

Ruthenium red

Ruthenium red is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Ruthenium red rather than just read about it. In short: Ruthenium red (RR), also known as ammoniated ruthenium oxychloride, is an inorganic compound used as a dye in histology to stain aldehyde fixed mucopolysaccharides. Structure The chloride has the chemical formula [Ru3O2(NH3)14]Cl6·4H2O.

Key takeaways

Ruthenium red belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Ruthenium red to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Ruthenium red from memory before moving on to harder problems.

Reference excerpt

Ruthenium red (RR), also known as ammoniated ruthenium oxychloride, is an inorganic compound used as a dye in histology to stain aldehyde fixed mucopolysaccharides.

Structure The chloride has the chemical formula [Ru3O2(NH3)14]Cl6·4H2O. A thiosulfate been characterized with the formula [Ru3O2(NH3)14](S2O3)3·4H2O. The cation is composed of a linear [(NH3)5-RuIII-O-(NH3)4RuIV-O-RuIII-(NH3)5]6+ backbone formed from three ruthenium coordination octahedra. The inhibition of mitochondrial Ca2+ uptake is attributed to an impurity with the formula μ-O-[(HCO2)(NH3)4Ru]2Cl3. This compound crystallizes in the orthorhombic system (space group Pnn2 (No. 34), a = 8.588 Å, b = 13.335 Å, c = 7.602 Å, cell volume = 870.6 Å3, Z = 2 units per cell).

Preparation The chloride is prepared by the aerial oxidation of ruthenium(III) chloride in aqueous ammonia solution. The thiosulfate is prepared by treating an aqueous solution of the chloride with sodium thiosulfate.

Uses Ruthenium red has been used as a pharmacological tool to study specific cellular mechanisms. Selectivity is a significant issue in such studies as RR is known to interact with many proteins. These include mammalian ion channels (CatSper1, TASK, RyR1, RyR2, RyR3, TRPM6, TRPM8, TRPV1, TRPV2, TRPV3, TRPV4, TRPV5, TRPV6, TRPA1, mCa1, mCa2, CALHM1) TRPP3, a plant ion channel, Ca2+-ATPase, mitochondrial Ca2+ uniporter, tubulin, myosin light-chain phosphatase, and Ca2+ binding proteins such as calmodulin. Ruthenium red displays nanomolar potency against several of its binding partners (e.g. TRPV4, ryanodine receptors,...). For example, it is a potent inhibitor of intracellular calcium release by ryanodine receptors (Kd ~20 nM). As a TRPA1 blocker, it assists in reducing the airway inflammation caused by pepper spray. RR has been used on plant material since 1890 for staining pectins, mucilages, and gums. RR is a stereoselective stain for pectic acid, insofar as the staining site occurs between each monomer unit and the next adjacent neighbor.

References

Illustrations

Worked examples

Example 1 — a first encounter with Ruthenium red

Start with the simplest possible case. Write down what Ruthenium red claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Ruthenium red before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Ruthenium red ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Ruthenium red

In research: Ruthenium red appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Ruthenium red in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Ruthenium red is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ammine complexes, Ruthenium complexes, Staining dyes, so understanding it makes those chapters shorter.
In everyday life: Look for Ruthenium red outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Ruthenium red in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ruthenium red means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Ruthenium red out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ruthenium red in simple terms?

Ruthenium red (RR), also known as ammoniated ruthenium oxychloride, is an inorganic compound used as a dye in histology to stain aldehyde fixed mucopolysaccharides. Structure The chloride has the chemical formula [Ru3O2(NH3)14]Cl6·4H2O.

Why does Ruthenium red matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Ruthenium red?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Ruthenium red.