FUNCTIONALIZED TRICARBOCYANINE DYES AS NEAR-INFRARED FLUORESCENT-PROBES FOR BIOMOLECULES

The syntheses of three novel functionalized tricarbocyanine dyes are d escribed. These dyes containing isothiocyanate and succinimidyl ester functional groups are reactive toward primary amines and can be used a s fluorescent probes for biologically pertinent compounds such as amin o acids and functionalized dideoxynucleotides. The absorption and fluo rescence maxima occur in the near-IR region of the spectrum (770-810 n m). The succinimidyl ester proved to be very sensitive to hydrolysis a nd was generated in situ to label amino acids. The isothiocyanates wer e less susceptible to hydrolysis and were conjugated using organic mod ified [40% (v/v) acetonitrile] buffers to amino acids. A dye with an a lkyl isothiocyanate moiety showed conjugation to amino-functionalized dideoxynucleotide triphosphates.