Peptidyl backbones of conjugates 6-9 were synthesized following the optimized protocol for the synthesis of peptides 3-5. After coupling and deprotection of the last amino acid residue, the peptidyl resin was manually coupled to three equivalents of cyanine dye 1 (for compounds 6-8) or 2 (for compound 9) in a polypropylene tube at 40 °C for overnight incubation. The desired conjugates were obtained after global deprotection, purification, and lyophilization.