DDAO Phosphate

DDAO-phosphate is a long-wavelength, phosphatase substrate for both solution-based assays[1,2] and the amplified detection of specific targets on blots[3,4]. Hydrolysis of the phosphate bond yields a brightly red-fluorescent product with absorption/emission maxima of ~646/659 nm that is efficiently excited by the 633 nm spectral line of the He–Ne laser. The shift of emission maxima between DDAO-phosphate and the dephosphorylated product is larger than 200 nm and permits both species to be easily distinguished. DDAO phosphate has good water solubility, a low KM and a high turnover rate.