Labeled 5-aminohexylacrylamido-dUTP (aha-dUTP) nucleotides are modified at the C-5 position of uridine with a unique hexylacrylamide linker, which serves as a spacer between the nucleotide and the dye. This spacer reduces interactions between the nucleotide and the dye, resulting in brighter conjugates and increased hapten accessibility for secondary detection reagents. Labeled nucleotides can be used to generate labeled nucleic acid hybridization probes for many molecular biology and molecular cytogenetics applications, including multicolor techniques.