Spectrophotometric characteristics and assay of pure pyronin Y
SummaryThe spectrophotometric characteristics of analytically pure pyronin Y have been investigated. Addition of metal ions (Fe3+, Zn2+, and Mg2+) and of dextrin were shown not to influence the absorption characteristics. The composition of the solvent strongly influenced the value of the extinction coefficient. Aqueous ethanolic solutions with a content of about 50% ethanol gave higher ε-values than those found for more concentrated ethanol solutions. The difference can be explained by the existence of a solvent-solute complex in the less concentrated ethanol solutions. A new spectrophotometric assay is proposed using the ε-value 11.7×104 lmol−1 cm−1 found in aqueous ethanol (52%) as standard.
Nucleic acid staining with the methyl green-pyronin method
SummaryWe compared the staining obtained using commercially available pyronin Y samples with that obtained using pure pyronin Y in a standardized methyl green-pyronin procedure. In addition, the importance of the dye content of the anhydrous dye was investigated by varying the dye content by the addition of pure pyronin Y to one of the commercially available pyronin Y samples. We found that, for routine histological work, commercially available pyronin Y samples may produce acceptable results provided the sample can be shown by spectrophotometry to contain at least 43% pyronin Y.
Global Islamic Politics
1. Introduction to Islam and Islamic Revivals. 2. Islam: A Vehicle for Political Action. 3. The Muslim Fundamentalists. 4. The Muslim Traditionalists. 5. The Muslim Modernists. 6. The Muslim Pragmatists. 7. Failure of Secular Ideologies and Developmental Crises. 8. Islamic Revivalism in the Arab-Israeli Context. 9. OPEC, OIC, and Islamic Politics. 10. The Islamic Revolution in Iran. 11. Islamic Revival in Central Asia. 12. Conclusion. Glossary of Islamic Terms.