Synthesis of a Far Red Absorbing Thiobarbituric Acid Oxonol Derivative as a Fluorescent Probe for Biological Applications

Abstract

A water-soluble oxonol dye containing a reactive hydroxysuccinimidyl ester suitable for reaction with biomolecules has been prepared. This fluorescent compound has 631 nm, ε^abs 147,000 M⁻¹ cm⁻¹, 659 nm, and quantum yield 0.30.

Acknowledgments

This work was supported by the Cooperative Research Centre for Diagnostic Technologies. We thank Dr. G. Neumann for recording the electrospray mass spectra.