Biotin-15-dCTP (5-{(7-N-(6-N-(biotinyl)aminocaproyl) -amino-4-oxa-hept-1-inyl)-2’-deoxycytidyl-5’-triphosphate is used for non-radioactive DNA labeling. Biotin-15-dCTP can be enzymatically incorporated into DNA via nick-translation, random priming, 3'-end terminal labeling or PCR. 15 is the number of carbon atoms in the backbone of linker between dUTP and biotin, this length of the linker is optimal for majority of the applications.