Standardization of an Aqueous Light Source Containing Luminol: Application to Measurement of Quantum Yields of Bioluminescent Reactions*

Abstract

A secondary liquid light standard containing luminol was calibrated at various temperatures and used to determine the photon quantum yields of some bioluminescent reactions. It was found that 10μM luminol in 0.009 N NaOH emitted 1.2×10¹⁰ (±12%) quanta/ml/see at the peak of light emission through an interference filter of peak light transmittance of 36% at 460 mμ and band width of 12 mμ, on reaction with 200 μM ferricyanide in the presence of 4 mM H₂O₂ at 20°C. A linear relationship was found between the peak light emission and the luminol concentration of a wide range. Convenient use of this light standard in determination of the photon quantum yields of some bioluminescent reactions is also reported and the values obtained were in reasonable agreement with those measured in other ways by previous workers.