dapi ( 4',6-diamidino-2-phenylindole ) , a fluorophor already known as a dna intercalator , was shown to bind specifically to a unique tubulin site as a dimer ( kd ( app ) = 43 +/- 5 microm at 37 degrees c ) or to tubulin associated in microtubules ( kd ( app ) = 6 +/- 2 microm at 37 degrees c ) with the same maximum enhancement in fluorescence .
C0041348
tubulin
C0026046
microtubules