coumarin label cpm The thiol-reactive coumarin, CPM is very weakly fluorescent until reacted with thiols producing a conjugate with excitation/emission maxima of ~384/470 nm. 2014-01-08T11:36:48Z MI:1329 7-diethylamino-3-(4' maleimidylphenyl)-4-methylcoumarin PSI-MI orchard