For biotin-16-UTP, biotin is bound to uridine triphosphate via an amide linkage. Biotin-16-UTP is a substrate for SP6, T3, and T7 RNA polymerase. It can replace UTP in the in vitro transcription reaction for RNA labeling. Linearized template DNA with T7, SP6, or T3 promoter is in vitro-transcribed with the corresponding RNA polymerases using ATP, GTP, CTP, UTP, and Biotin-16-UTP, respectively.