Uses a unique hexylacrylamide linker that acts as a spacer between the nucleotide and the dye in the uridine Modification marker 5-aminoacrylamide-dUTP (aha-dUTP) nucleotide at position C-5. This spacer reduces nucleotide-dye interactions, resulting in brighter conjugates and enhanced hapten accessibility to secondary detection reagents. Labeled nucleotides can be used to generate labeled nucleic acid hybridization probes for a variety of molecular biology and molecular cytogenetic applications, including multicolor techniques.