Sperm chromatin assessment
David K. Gardner, Ariel Weissman, Colin M. Howles, Zeev Shoham in Textbook of Assisted Reproductive Techniques, 2017
TB staining follows the principle of metachromasia in which a dye can absorb light at different wavelengths and can change color without changing chemical structure. Sperm smears are air-dried, fixed in freshly made 96% ethanol-acetone (1:1) at 4°C for at least 30 minutes, hydrolyzed in 0.1 N HCl at 4°C for five minutes, and rinsed three times in distilled water for two minutes each. Smears are stained with 0.05% TB for five minutes. The staining buffer consists of 50% citrate phosphate (McIlvain buffer, pH 3.5). Permanent preparations are dehydrated in tertiary butanol twice for three minutes each at 37°C and in xylene twice for three minutes each; the preparations are embedded in DPX (a mixture of distyrene, a plasticizer, and xylene). Sperm heads with good chromatin integrity stain light blue and those of compromised integrity stain violet (purple) (162). The results of the TB test are visualized using light microscopy. Based on the different optical densities of cells stained with TB, the image analysis cytometry test is elaborated (Figure 6.1a) (144).
Thionine-positive cells in relation to parasites
G. F. Wiegertjes, G. Flik in Host-Parasite Interactions, 2004
The mast cells and basophils were first described in the late 19th century by the German physician and biochemist Paul Ehrlich. He described the mast cells and the basophils as large, distinctively stained cells containing basophilic granules. The mast cells and basophils can be histologically recognized by their ability to have their granules metachromatically stained with thionine. Only a few tissue elements display metachromasia, changing in the tissues from blue (the usual orthochromatic form) to purplish red or reddish purple. Thus, thionine and other cationic dyes, called metachromatics, are of considerable value in the study of specific elements of connective tissue. Among other metachromatic dyes the most commonly used are toluidine blue O, methylene blue, gallocyanin, and pinacyanole (Schubert and Hamerman, 1956). The cytoplasmic granules of these cells contain many biologically active substances, which contribute to their roles in host defence against parasites (Galli et al., 1984). The roles of mast cells in the expression of host resistance to certain parasites are dependent on factors such as parasite species and the infection site (Costa et al., 1997; Galli and Dvorak, 1995; Gill, 1986; Neitz et al., 1993).
Cystic Fibrosis
Stephen D. Litwin in Genetic Determinants of Pulmonary Disease, 2020
Although the first indication that there was a cellular abnormality in patients with CF was the recognition by Danes and Beam [49] of metachromatic staining material in cultured cells, it remains evident that this is a rather insensitive and crude indication of the presence of a cellular abnormality [47]. Metachromasia was initially detected by the use of cationic toluidine blue O which not only stains mucopolysaccharides metachromatically but also reacts with a number of negatively charged cellular substances, including lipids and nucleic acids. The use of the dye alcian blue [50] increases the specificity of the metachromasia somewhat since at high electrolyte concentrations only mucopolysaccharides stain. As cultured CF cells did not show alcianophilia, it could be concluded, therefore, on histochemical grounds, that the metachromatic staining with toluidine blue was unlikely to be due to mucopolysaccharides.
Systematic review of accuracy of reporting of Congo red-stained amyloid in 2010–2020 compared with earlier
Published in Annals of Medicine, 2022
Alexander J. Howie, Mared P. Owen-Casey
The birefringence of Congo red-stained amyloid is shown by the appearance of brightness against a dark background when the specimen is examined between crossed analyser and polariser [1–5]. Eight papers incorrectly said that there was green dichroism. Dichroism is shown with either an analyser or a polariser, but not both, and means that a material absorbs some wavelengths of light polarised in one direction of orientation of the material, and so appears a particular colour, red in the case of Congo red-stained amyloid, but does not absorb light polarised at right angles, and so the material appears in theory colourless, but in practice a lighter shade of the same colour, still red in this case [3]. Three papers used the term green metachromasia when talking about polarised light, but metachromasia means that there is a change of colour when a dye is examined in ordinary, unpolarised light [5]. Two papers used the term green fluorescence in polarised light, but fluorescence means emission of longer wavelengths, usually in the visible spectrum, than the illuminating wavelengths, usually ultraviolet radiation.
Frequencies of Immune Cells in the Human Small Bowel During Normal Gestation and in Necrotizing Enterocolitis
Published in Fetal and Pediatric Pathology, 2019
Paul Peterslund, Lene Rasmussen, Niels Qvist, Tine Plato Hansen, Steffen Husby, Sönke Detlefsen
The ROI in which cell frequency was counted varied from specimen to specimen, due to the differences in GA and heterogenic tissue samples. A total of 36 NSB specimens, with GA ranging from 12 to 41 weeks, and 8 USB cases, with GA ranging from 24 to 33 weeks, were sampled with two different methods and six different stains in ROI between 1.84 and 9.26 mm2. Some toluidine-blue-stained slides from early GA specimens had areas of metachromasia in the submucosa, which hindered proper sampling with TissuemorphDP®, causing cell underestimation and decreased ROIs. In these specimens, a preview was done in the field of view (FOV), and any area labeled as a “mast cell” by the TissuemorphDP® classifier was manually checked for verification. This was repeated until no false positives were found in the ROI. One slide had to be excluded from TissuemorphDP® sampling due to excessive metachromasia.
Osteocalcin, Azan and Toluidine blue staining in fibrous dysplasia and ossifying fibroma of the jaws
Published in Alexandria Journal of Medicine, 2018
Samuel Ebele Udeabor, Akinyele Olumuyiwa Adisa, Anna Orlowska, Poju Chia, Robert A. Sader, Shahram Ghanaati
Distinguishing between FD and OF using either the genetic or immunohistochemical tests in each case of a FOL may not be feasible in all cases for all laboratories due to overhead costs and or patients inability to afford such tests. Also the results of tests may be needed in a relatively short turn-around time and this may not be possible with genetic or immunohistochemical analysis. Thus, we therefore conduct this study to detect any correlation between relatively simple histo-morphometric analysis with Azan and Toluidine blue as compared with immunohistochemistry by osteocalcin. These may offer a relatively less complex and quicker method for appropriate diagnosis. Azan is a trichrome stain that uses three anionic dyes to mark different tissues histologically. It is an improvement over the traditional Mallory’s method and stains muscle fibers red and cartilage/bone matrix blue.8 Toluidine blue is an acidophilic metachromatic dye that selectively stains acidic tissue components (sulfates, carboxylates, and phosphate radicals). It has been extensively used as a vital stain for mucosal lesions but has also found applications in tissue sections to specifically stain certain components owing to its metachromatic property.9
Related Knowledge Centers
- Cartilage
- Color
- Dye
- Ester
- Nucleic Acid
- Polyelectrolyte
- Tissue
- Staining
- Toluidine Blue