I have heard that fluorescent dyes can't be completely cleaned out of our HPLC because they become too firmly attached to the teflon seals in the injector, etc. Carry over of the dye has been shown by fluorescence detection. If we're seeing ghost peaks, shouldn't a better cleaning protocol or perhaps a replumbing of the injector suffice? Is anyone else familiar with carry-over problems with fluorescent dyes in Waters Systems?