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|Section2= |Section3= }} Alcian blue or alcian blue () is any member of a family of polyvalent basic dyes, of which the Alcian blue 8G (also called Ingrain blue 1, and C.I. 74240, formerly called Alcian blue 8GX from the name of a batch of an ICI product) has been historically the most common and the most reliable member.〔(''Stains and Cytochemical Methods'', By M. A. Hayat, 1993 ed, Chapter 8, page 80 )〕 It is used to stain acidic polysaccharides such as glycosaminoglycans in cartilages and other body structures, some types of mucopolysaccharides, sialylated glycocalyx of cells etc. For many of these targets it is one of the most widely used cationic dyes for both light and electron microscopy. Use of alcian blue has historically been a popular staining method in histology especially for light microscopy in paraffin embedded sections and in semithin resin sections. The tissue parts that specifically stain by this dye become blue to bluish-green after staining and are called "Alcianophilic" (akin to "eosinophilic" or "sudanophilic"). Alcian blue staining can be combined with H&E staining, PAS staining and van Gieson staining methods. Alcian blue can be used to quantitate acidic glycans both in microspectrophotometric quantitation in solution or for staining glycoproteins in polyacrylamide gels or on western blots. Biochemists had used it to assay acid polysaccharides in urine since the 1960s for diagnosis of diseases like mucopolysaccharidosis but from 1970's, partly due to lack of availability of Alcian and partly due to length and tediousness of the procedure, alternative methods had to be developed e.g. Dimethyl methylene blue (DMB) method.〔''Clinical Chemistry'' March 1989 vol. 35 no. 3 374–379〕 Prof. J. E. Scott, the first person outside the dye Industry to crack the chemical secret of this dye comments: :"Probably no other dyestuff has been applied to such wide variety of problems in biology and medicine. On the other hand, no other dyestuff had such a chequered history as AB.〔(''Eur J Oral Sci.'' 1996 Feb;104(1):2–9. "Alcian blue. Now you see it, now you don't". Scott J. E. )〕" In addition to its wide use as a stain Alcian blue has also been used in other diverse applications e.g. gelling agent for lubricating fluids, modifiers for electrodes, charged coating agents etc. ==History== The Monstral blue found to coat the inside of copper vessels used to process phthalic acid derivatives had led to the discovery of Phthalocyanine in 1907. Attracted by the brilliance, stability and insolubility of this chromophore, attempts were made to reversibly modify it so that it would be carried into fabric in a solution and then easily precipitated (ingrained) into an unleachable but finely well dispersed deposit (hence the name "''ingrain dyeing''"). From this attempt, Alcian blue (Ingrain blue 1) was first synthesized by the ICI dyestuffs department under N. H. Haddock and C. Wood in the early 1940s and patented in 1947, originally as a textile dye. In 1950 it was used by Steedman as a selective dye for mucins.〔Steedman, H. F., ''Microsc. Sci.'', v. 91, 477–479 (1950)〕 While the popularity of Alcian blue expanded exponentially, the difficulty involved in its production due to environmentally hazardous intermediate steps made its availability difficult and ICI stopped producing it by 1973. Many of the alternate sources sold similar looking color products with unreliable staining. Prof J. E. Scott worked to decipher the chemistry of Alcian blue, which was known only to the Industry but kept as a tight trade secret. After spending 3 man-years of effort (which would have been unnecessary had the industry released the results) in 1972 he published the structure of Alcian blue and was able to get ICI to confirm it in 1973, incidentally in the same time that ICI also had just stopped producing it.〔(''Histochemistry and Cell Biology'' Volume 37, Number 4 (1973), 379–380, "Alcian dyes: I.C.I. cease manufacture and release details of composition" J. E. Scott )〕 After the interim crisis since the 1970s when ICI had to stop, there have now been environmentally safe alternative industrial manufacturing of this dye that is supposed to work as well as 8GX but is called 8G since it is made differently.〔http://www.anatechltdusa.com/Innovators/6_InnDyes.html〕 In attempt to answer what was the importance of discovering an alternative method of manufacturing this compound, a company (Anatech Ltd, USA) that remanufactured Alcian blue says: :"Alcian blue is highly selective for the tissue substances (given the proper solution pH), and forms insoluble complexes that withstand harsh subsequent treatment (like PAS) without destaining. That is what makes this dye so important. Do any other dyes have this attribute? Yes, two others to be exact, out of thousands listed in the Colour Index and Conn's Biological Stains." These two are 'Alcian yellow' and basic red 18, which are again both equally unavailable and also lack the brilliant contrast of the blue. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Alcian blue stain」の詳細全文を読む スポンサード リンク
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