| abstract |
The invention pertains to a near-infrared fluorescent dye that is cell permeable and can be attached to selected proteins in living cells. The dye has the general formula n n n n n n n n n n or its corresponding spirolactone n n n n n n n n n n whereinn Y is chosen from the group consisting of Si, Ge and Sn; R 0 is —COO − or COOH; R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are substituents, including hydrogen, independently from each other. nn The dye (i) absorbs and emits light at wavelengths above 600 nm; (ii) possesses high photostability; (iii) has high extinction coefficients and high quantum yields; (iv) can be derivatized with different molecules; and (v) is membrane-permeable and shows minimal background binding to biomolecules and biomolecular structures. |