{"id":534,"date":"2022-10-12T10:21:18","date_gmt":"2022-10-12T08:21:18","guid":{"rendered":"https:\/\/modafinil.pl\/sklep\/methylene-blue-methylene-blue-purity-%e2%89%a5-99-99-1000mg\/"},"modified":"2026-10-03T06:11:57","modified_gmt":"2026-10-03T04:11:57","slug":"methylene-blue","status":"publish","type":"product","link":"https:\/\/modafinil.pl\/en\/sklep\/methylene-blue\/","title":{"rendered":"Methylene Blue (CAS 61-73-4) \u2014 laboratory reagent 1000 mg, purity \u2265 99.50%"},"content":{"rendered":"

[7-(Dimethylamino)phenothiazin-3-ylidene]dimethylazanium chloride<\/strong> (common name: methylene blue, methylthioninium chloride), crystalline powder, 1000 mg pack. Material intended exclusively for laboratory and analytical in vitro research<\/strong>. This product is not intended for human or animal consumption<\/strong>; it is not a medicinal product, food supplement, foodstuff or cosmetic.<\/p>\n

Three distinct entities that must not be confused<\/h2>\n

Methylene blue is a special case in this catalogue: the same molecule functions simultaneously as the active substance of registered medicinal products administered intravenously<\/strong> and as a common staining reagent and analytical standard. Separating the layers is just as important here as for substances with a clearly \u201cpharmaceutical\u201d lineage:<\/p>\n\n\n\n\n\n\n\n
Separating the layers: substance \u2014 medicinal product \u2014 reagent<\/caption>\n
Entity<\/th>\nWhat it is<\/th>\nWhat it concerns<\/th>\n<\/tr>\n<\/thead>\n
Chemical substance
methylene blue, CAS 61-73-4<\/th>\n		A chemical concept \u2014 a phenothiazinium cation with chloride as the counter-ion. In itself it is neither a medicine nor a reagent; its status is conferred only by the form in which it has been manufactured and authorised.<\/td>\nchemistry, substance registers<\/td>\n<\/tr>\n
Medicinal product
e.g. solutions for injection based on methylthioninium chloride, registered under trade names such as Proveblue<\/th>\n		A pharmaceutical preparation: a strictly defined concentration of solution for intravenous administration, manufacture under GMP, registration dossier, safety monitoring. Used in the treatment of acquired methaemoglobinaemia and studied as an adjunctive drug in the therapy of Plasmodium falciparum<\/em> infections. It is this entity that the clinical studies and toxicological reviews<\/strong> cited below concern.<\/td>\nclinical pharmacology, toxicology<\/td>\n<\/tr>\n
Chemical reagent
the material offered here<\/th>\n		Material for laboratory and analytical work \u2014 a dye, a spectrophotometric standard, a redox label. It does not have, and cannot have, any authorisation for use in humans or animals<\/strong> \u2014 it has no pharmaceutical form and no medicinal product documentation.<\/td>\nanalytics, chemistry, reference standards<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The consequence is unambiguous.<\/strong> The research results referred to later on this page were obtained either with a registered medicinal product<\/strong> administered intravenously under medical supervision, or with the substance used under laboratory experimental conditions or in preclinical animal studies<\/strong>. None of these studies was conducted with an analytical reagent<\/strong>, and none of these results transfers to the material offered. The reagent is not a form in which the substance has ever been administered to humans, and it cannot be used in that way.<\/p>\n

Reagent identification sheet<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Registry data and identifiers \u2014 methylene blue<\/caption>\n
Systematic name (IUPAC)<\/th>\n[7-(dimethylamino)phenothiazin-3-ylidene]dimethylazanium chloride<\/td>\n<\/tr>\n
Common name<\/th>\nmethylene blue<\/td>\n<\/tr>\n
INN \/ pharmacopoeial name<\/th>\nmethylthioninium chloride<\/td>\n<\/tr>\n
CAS number<\/th>\n61-73-4<\/td>\n<\/tr>\n
Molecular formula<\/th>\nC16<\/sub>H18<\/sub>ClN3<\/sub>S<\/td>\n<\/tr>\n
Molar mass<\/th>\n319.9 g\u00b7mol\u22121<\/sup><\/td>\n<\/tr>\n
Monoisotopic mass<\/th>\n319.0910 Da<\/td>\n<\/tr>\n
InChIKey<\/th>\nCXKWCBBOMKCUKX-UHFFFAOYSA-M<\/td>\n<\/tr>\n
SMILES<\/th>\nCN(C)C1=CC2=C(C=C1)N=C3C=CC(=[N+](C)C)C=C3S2.[Cl-]<\/td>\n<\/tr>\n
PubChem CID<\/th>\n6099<\/a><\/td>\n<\/tr>\n
ChEMBL<\/th>\nCHEMBL3942629<\/td>\n<\/tr>\n
Form<\/th>\ncrystalline powder (basic dye); aqueous solution intensely blue<\/td>\n<\/tr>\n
Purity<\/th>\n\u2265 99.5%<\/td>\n<\/tr>\n
Intended use<\/th>\nresearch reagent \u2014 not for human or animal consumption<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Origins of the molecule: from aniline dye to the phenothiazine core<\/h2>\n

Methylene blue is not a product of medicinal chemistry \u2014 it is a by-product of the aniline dye industry<\/strong> of the second half of the nineteenth century, which only after the fact found applications in biology and pharmacology. This distinguishes it from most substances in this catalogue: its career began on the production floor of a chemical works, not in a pharmacological laboratory.<\/p>\n

Born in a dye factory (1876)<\/h3>\n

The compound was synthesised by Heinrich Caro in 1876 at BASF<\/strong> \u2014 a fact documented in the historical paper by Krafts and co-workers [1<\/a>]. Six years later Robert Koch used methylene blue in the discovery of the tubercle bacillus, and in 1880 Paul Ehrlich described the concept of \u201cneutral\u201d dyes \u2014 mixtures of an acidic and a basic dye for differentiating peripheral blood cells [1<\/a>].<\/p>\n

The dye that taught biology to see<\/h3>\n

In 1886 Bernthsen obtained from the decomposition of methylene blue a derivative named methylene azure. In 1891 Malachowski developed a method combining eosin with \u201cripened\u201d methylene blue which for the first time revealed the nuclei of malaria parasites in a blood smear \u2014 Romanowsky reproduced this effect by an independent method. The following decades brought a series of refinements to the staining technique: Nocht (1899), Jenner (1899, methanol as fixing solvent), Wright (1902) and finally Giemsa (1902), who perfected the demethylation of the dye and added glycerol as a stabiliser. Malachowski\u2013Wright\u2013Giemsa staining remains to this day the worldwide standard for the microscopic diagnosis of malaria<\/strong> [1<\/a>]. The context of this diagnostic revolution \u2014 dyes as a tool that laid the foundations of modern cell biology (Virchow, Papanicolaou) and of the neuron theory (Golgi, Cajal) \u2014 is described in Chast’s historical review [2<\/a>].<\/p>\n

The phenothiazine core: from methylene blue to chlorpromazine<\/h3>\n

Methylene blue is the first member of the family of phenothiazine dyes<\/strong> \u2014 a tricyclic system with nitrogen and sulfur atoms in the central ring. Attempts to modify this core in search of an antimalarial drug (a continuation of Ehrlich’s work) did not yield an effective antimalarial compound, but led organic chemistry to a new class of antihistamine and sedative drugs: promethazine, promazine and finally chlorpromazine \u2014 the first effective antipsychotic drug<\/strong>, as described by Frankenburg and Baldessarini [3<\/a>]. The history of this line of development \u201cfrom methylene blue via chlorpromazine to modern neuroleptics\u201d, in the context of Ehrlich’s receptor concept, was traced by Kristiansen [4<\/a>]. For the laboratory this has a classification consequence: methylene blue is sometimes cited as the parent compound of the entire phenothiazine family, not as a side branch of it.<\/p>\n

Timeline<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
Timeline: from the synthesis of the dye to modern analytics<\/caption>\n
1876<\/th>\nsynthesis of the compound by Heinrich Caro at the BASF works [1<\/a>]<\/td>\n<\/tr>\n
1880<\/th>\nEhrlich describes the concept of \u201cneutral\u201d dyes for differentiating blood cells [1<\/a>]<\/td>\n<\/tr>\n
1882<\/th>\nKoch uses methylene blue in the discovery of the tubercle bacillus [1<\/a>]<\/td>\n<\/tr>\n
1886\u20131891<\/th>\nBernthsen obtains methylene azure; Malachowski and Romanowsky reveal malaria parasites in a blood smear [1<\/a>]<\/td>\n<\/tr>\n
1899\u20131902<\/th>\nNocht, Jenner, Wright and Giemsa refine the staining technique \u2014 Malachowski\u2013Wright\u2013Giemsa staining is born [1<\/a>]<\/td>\n<\/tr>\n
1st half of the twentieth century<\/th>\nmodifications of the phenothiazine core in search of an antimalarial drug lead to promethazine, promazine and chlorpromazine [3<\/a>][4<\/a>]<\/td>\n<\/tr>\n
twentieth century<\/th>\nmethylene blue establishes its position as the standard antidote in acquired methaemoglobinaemia [6<\/a>][7<\/a>]<\/td>\n<\/tr>\n
2017<\/th>\nex vivo study of the activity of a modern methylthioninium chloride preparation against multidrug-resistant strains of Plasmodium falciparum<\/em> \u2014 a possible return of the compound to the antimalarial role it held over a century ago [5<\/a>]<\/td>\n<\/tr>\n
2012\u20132023<\/th>\ndevelopment of LC-MS\/MS and UPLC-MS\/MS methods for determining residues of the compound in food of aquatic origin, and of electrochemical methods using it as a redox label [10<\/a>][9<\/a>][14<\/a>]<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Four research streams that shaped knowledge of this molecule<\/h2>\n

Unlike substances with a single research centre, the literature on methylene blue divides into four largely independent streams. For a laboratory using this reagent this matters in practice \u2014 when looking for a specific piece of information, it helps to know in which stream to look for it.<\/p>\n