The staining properties of pyridylazophenol analogs in histochemical staining of a metal

✍ Scribed by Y. Sumi; T. Inoue; T. Muraki; T. Suzuki

• Book ID: 104787044
• Publisher: Springer
• Year: 1983
• Tongue: English
• Weight: 730 KB
• Volume: 77
• Category: Article
• ISSN: 1432-119X
• DOI: 10.1007/bf00496630

✦ Synopsis

The compound 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP) was found capable of staining very small amounts of metals in tissue. This finding stemmed from the examination of the staining properties of pyridylazophenol analogs; 2-(2-pyridylazo)-phenol, 2-(2-pyridylazo)-5-dimethylaminophenol, 1-(2-pyridylazo)-2-naphthol, 4-(2-pyridylazo)-resorcinol, and Br-PADAP. The unusually high sensitivity of Br-PADAP is attributed to the presence of an alkylamino group at the 5-position of the benzene ring. The presence of this alkylamino group forms a charged quinoid structure, and contributes resonance and optimum solubility to the hybrid by introducing a bromine atom into the pyridine ring. We report the staining results obtained from a variety of metals and the molar absorptivity of their metal chelates.