Metachromatic Granules

On the other hand, Widra found metachromatic granules to contain protein-bound lipide, RNA, and polyphosphates. 

The oldest and most extensively used method for determination of PolyPs in biological materials, although of course the least accurate, is based on the staining of cells and tissues by certain basic dyes such as toluidine blue, neutral red and methylene blue. The presence of condensed phosphates in the organisms is judged by the appearance in the cells of metachromatically stained granules, or volutin granules. 

It should be noted, however, that, despite the fact that in most cases the cytochemical detection of metachromatic granules is associated with the actual presence of PolyPs in the organism, such methods must nevertheless be carried out with great caution. This is primarily due to the fact that basic dyes are also capable of staining other polymeric compounds present in the cells. 

The presence of PolyPs in these granules is indicated by the following indirect observations. First, volutin granules undergo metachromatic staining by basic dyes, 4,6 -diamino-2-phenylindole (DAPI) fluorescence shifts, and other reactions specific for PolyPs (see... 

It has already been pointed out that it is not only PolyPs but other anionic polymers, such as [X)I y-ft -hy< I rox ybutyrate, which may form metachromatic granules in the cells of prokaryotes. However, recently a number of methods for differential staining of PolyPs and polyhydroxyalkanoate-containing granules in cells have been developed (see the review of Serafim et al, 2002). 

Figure 5.2 PolyPs in different compartments of the cells of Saccahromyces cerevisiae (lead staining) (Vorfiek et al., 1982) (a) PolyP in vacuoles (the arrow indicates a metachromatic granule) (b) PolyP in a cell nucleus (the arrow indicates the nuclear membrane) (c) PolyP in internal cell wall layers at phosphate overplus (d) PolyP in vacuoles after phosphate overplus the scale bars are equal to 0.5 /xm.

R. Minck and A. Minck (1949). Constitution of diphtheria bacillus, nuclear apparatus and metachromatic granulations. C.R. Acad. Sci. Paris, 228, 1313-1315. 

Mucosulphatidosis is caused by arylsulphatase deficiency (types A, B and C). Metachromatic granules are found mostly in portal macrophages and less frequently in hepatocytes or Kupffer cells. 

Uses Pigment for paints, printing inks solvent dye for ballpen inks, printer ribbons, lacquers staining metachromatic granules of diphtheria organisms (with crystal violet and Bismarck brown Y)... 

Metachromatic granule A polyphosphate granule that exhibits metachromasia. Known also as volutin. 

Mast cells with their metachromatic granules (0.3 to 1.0 [tm in diameter) as their hallmarks produce histamine, which has marked vasoactive effects and also seems to enhance oxygen radical formation by phagocytes (Friedl et al. 1989). 

Fig. 3-44). Careful examination of all organs might reveal the presence of metachromatic granules in the renal tubules, the gall bladder, and the intrahepatic bile ducts. In metachromatic leukodystrophy, the levels of sulfatides increase more (2 to 4 times) in the white than in the grey matter. The increase in sulfatides is associated with an increase in cerebrosides. The concentration of the other lipids is nearly normal. The proportion of sphingolipids containing long-chain fatty acids (18 or more carbons) is decreased in metachromatic leukodystrophy, and the ceramides found in the accumulating lipids contain mainly short-chain fatty acids. The relationship between the lipid accumulation and the demyelinization and the symptoms of leukodystrophy remains to be elucidated.

Strullu DG, Gourret JP, Garrec JP, Pourcy A (1981) Ultrastructure and electron-probe microanalysis of the metachromatic vacuolar granules occurring in Taxus mycorrhizas. New Phytol 87 537-545... 

The authors (Pitcher and Collins, 1991) described the bacteria of the new species as Gram-positive, non-motile and non-spore-forming, containing metachromatic granules. Most strains can reduce nitrate and some of them also nitrite. Some strains can hydrolyze urea and starch. Mycolic acids are not found. The major respiratory quinone is MQ-9(H4). 

Heparin combines readily with basic dyes with toluidine blue, the reaction is metachromatic and results in a deep purple color. Using this procedure, heparin has been detected mainly in the msist cells, which are located in connective tissues, especially alongside the capillaries and in the walls of blood vessels. It seems also to be present in basophilic leucocytes, in the stomach, and in the intestinal wall. In the cell itself, heparin seems to be localized in the granules and absent from the cytoplasm. A substance called "mactin , which is probably identical to heparin, has been prepared from mollusca . ... 

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