The buffer for Nluc reactions
consisted of 100 mM MES pH 6.0, 1 mM CDTA, 0.5% (v/v) Tergitol, 0.05%
(v/v) Mazu DF 204, 150 mM KCl, 1 mM DTT, and 35 mM thiourea. Furimazine
substrate was added to give a working reagent that was then added
in equal volume directly to assay samples (final concentration of
furimazine in the assay was commonly between 10 and 50 μM).
Complete methods and additional details can be found in the Supporting Information.