Nucleoside-5′-triphosphates and phosphoramidites which carry a residue absorbing in the long wavelength region, preferably a carbocyanine group of the general formula (I), on the base portion or on the phosphorus atom in which R1 and R2 each denote hydrogen or together form a phenyl residue; R3 denotes hydrogen if linkage with the nucleotide is via the R4 position or it denotes a —NHCS— group if linkage with the nucleotide is via the R3 position; both R4 and R5, or R5, alone denote an alkylsulfonyl group with n being a number from 3 to 5 or R4 represents a —NHCS— group with n being a number from 3 to 8, as well as the use of the compounds to label, detect and sequence nucleic acids.