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 or its corresponding spirolactone wherein Y is chosen from the group consisting of Si, Ge and Sn; R0 is —COO? or COOH; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15 and R16 are substituents, including hydrogen, independently from each other. 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.

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 or its corresponding spiro ac one wherein Y is chosen from the group consisting of Si, Ge and Sn; R0 is —COO? or COOH; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R15 and R16 are substituents, including hydrogen, independently from each other. 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.

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 or its corresponding spirolactone wherein Y is chosen from the group consisting of Si, Ge and Sn; R0 is —COO? or COOH; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15 and R16 are substituents, including hydrogen, independently from each other. 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.

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 or its corresponding spirolactone wherein Y is chosen from the group consisting of Si, Ge and Sn; R0 is —COO? or COOH; R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15 and R16 are substituents, including hydrogen, independently from each other. 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.