Biotin-11-dUTP can be enzymatically incorporated into DNA via nick translation, random priming, or 3'-end terminal labeling. The number '11' is the number of atoms in the linker between biotin and dUTP. Biotium also offers biotin-16-dUTP and biotin-20-dUTP . The length of the linker affects the incorporation efficiency of the biotin-dUTP probe into DNA using DNA polymerases, and it also affects biotin/avidin or biotin/streptavidin. In general, the shorter the linker, the more efficiently the biotin-dUTP is incorporated into DNA by DNA polymerases. On the other hand, the longer the linker, the better biotin can interact with avidin or streptavidin.