aha-dUTP (5-aminohexylacrylamido-dUTP) is modified at the C-5 position of uridine with a unique hexylacrylamide moiety. aha-dUTP can be used to produce amine-modified DNA by conventional enzymatic incorporation methods such as reverse transcription. The amine-modified DNA can then be labeled with any amine-reactive dye to generate labeled nucleic acid hybridization probes. This two-step labeling technique consistently results in a uniform and high degree of DNA labeling that is difficult to obtain by other methods. In addition to this 50 mM solution in TE (50 µL unit size), it is available as a 2 mM solution in TE (500 µL unit size, A32760).