On the nature of Romanowsky dyes and the Romanowsky-Giemsa effect.
ABSTRACT This paper reviews the nature of Romanowsky staining and the relationship between Romanowsky dyes and the Romanowsky-Giemsa effect (RGE). On blood and bone marrow smears the RGE is characterized by a purple colouration of nuclei and neutrophil granules. The nuclear purple contrasts strongly with the blue cytoplasmic staining of cells rich in RNA. Requirement for the occurrence of RGE are: I A cationic dye: The best dye is azure B and, though azure A gives the nuclear purple colour, the cytoplasmic blue is inferior. No other cationic dye such as methylene blue is suitable. 2 An anionic dye: Most commonly eosin Y is used, but it can be replaced by the erythrosins. Full halogenation of the fluorescein (four atoms of bromine or iodine) is not necessary. Phloxine and rose bengal are unsuitable. 3 An appropriate substrate: These are proteins with acidic side groups or proteins bound to a polyanion. For the interaction with the dyes substrates must provide a suitable three-dimensional network which is why the RGE is not obtained in solutions. A tentative theory of RGE is advanced and briefly discussed.
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ABSTRACT: Approximately 60% of emerging viruses are of zoonotic origin, with three-fourths derived from wild animals. Many of these zoonotic diseases are transmitted by rodents with important information about their reservoir dynamics and pathogenesis missing. One main reason for the gap in our knowledge is the lack of adequate cell culture systems as models for the investigation of rodent-borne (robo) viruses in vitro. Therefore we established and characterized a new cell line, BVK168, using the kidney of a bank vole, Myodes glareolus, the most abundant member of the Arvicolinae trapped in Germany. BVK168 proved to be of epithelial morphology expressing tight junctions as well as adherence junction proteins. The BVK168 cells were analyzed for their infectability by several arbo- and robo-viruses: Vesicular stomatitis virus, vaccinia virus, cowpox virus, Sindbis virus, Pixuna virus, Usutu virus, Inkoo virus, Puumalavirus, and Borna disease virus (BDV). The cell line was susceptible for all tested viruses, and most interestingly also for the difficult to propagate BDV. In conclusion, the newly established cell line from wildlife rodents seems to be an excellent tool for the isolation and characterization of new rodent-associated viruses and may be used as in vitro-model to study properties and pathogenesis of these agents.Virology Journal 01/2011; 8:339. · 2.09 Impact Factor
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ABSTRACT: The performance characteristics of the XE-2100 (Sysmex, Kobe, Japan) automated immature granulocyte (IG) count were studied. The automated IG count was compared with the manual morphology count and with a proposed reference flow cytometric count. The comparison data were analyzed by both least-squares and Passing-Bablok regression analysis. Long-term imprecision using preserved blood quality control specimens at different levels showed a range from 2.59% to 3.57% coefficient of variation (CV) for within-run imprecision and 3.57% to 6.85% CV for total imprecision. The within-run reproducibility performed using fresh blood on 3 different specimens showed a range from 5.55% to 8.24% CV. The counts were stable at both room temperature and after refrigeration for 24 hours.Passing-Bablok regression analysis showed excellent agreement between the proposed reference flow cytometric IG count and the XE-2100 IG count, while there was less agreement with the manual morphology count. Our results indicate that the automated IG count can replace the manual morphology count for IG counting in the clinical laboratory. The results also confirm that the flow cytometric IG count is superior to and can replace the manual morphology count as a reference method for IG counting.American Journal of Clinical Pathology 10/2007; 128(3):454-63. · 2.88 Impact Factor
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ABSTRACT: The components of the blood stain, eosin and methylene blue, were introduced by Baeyer and Caro, respectively. Methylene blue was used primarily for detecting Mycobacterium tuberculosis until Ehrlich in 1880 mixed methylene blue with acid fuchsin to produce what he termed a "neutral stain," which allowed differentiation of blood cells. Eight years later, Chęciń ski changed the acidic component of the dye to eosin. Plehn subsequently altered the proportions of eosin and methylene blue to produce a greater range of red and blue hues. In 1891, Malachowski and Romanowsky independently developed stains composed of eosin and "ripened" methylene blue that not only differentiated blood cells, but also demonstrated the nuclei of malarial parasites. A number of "ripening" or "polychroming" techniques were investigated by different groups, but the aqueous dye solutions produced were unstable and precipitated rapidly. Subsequently, methanol was introduced as a solvent for the dye precipitate and techniques were developed that utilized the fixative properties of the methanolic solution prior to aqueous dilution for staining. This avoided the troublesome process of heat fixation of blood films. Giemsa further improved these techniques by using more controlled methods of methylene blue demethylation. In addition, he used measured amounts of known dyes and increased dye stability by adding glycerol to the methanol solvent. With the outbreak of World War I, it became difficult to obtain German dyes outside of Germany; during the World War II, it became impossible. In their effort to improve the inferior American versions of Giemsa's stain, Lillie, Roe, and Wilcox discovered that the best staining results were obtained using pure methylene blue, one of its breakdown products (azure B) and eosin. These three substituents remain the major components of the stain to this day.Biotechnic & Histochemistry 02/2011; 86(1):7-35. · 0.67 Impact Factor