Non-exponential decay of indole fluorescence — the red-edge effect

Abstract

The fluorescence of indole in glycerol decays exponentially at both 22° and −80°C for 280 nm excitation. Under 296 nm excitation the 22°C emission decay is exponential, but at −80°C, a second shorter lived (1.3 ns) component is also detected. The relevance of this result to the determination of protein fluorescence lifetime is described.