Biotin-dT can replace dT residues within the oligonucleotide sequence. 5'-Biotin phosphoramidite can be added ONLY ONCE to the 5'-terminus of an oligonucleotide. However, the DMT group on the biotin can be used in RP cartridge and HPLC purification techniques. PC Biotin is a photocleavable 5'-biotin phosphoramidite. BiotinTEG CPG and Protected BiotinLC Serinol CPG are designed for the direct synthesis of oligonucleotides containing biotin at the 3' terminus.
Desthiobiotin is a biotin analogue that exhibits lower binding to biotin-binding proteins such as streptavidin. This biotin analogue is lacking the sulfur group from the molecule and has a dissociation constant (Kd) several orders of magnitude less than biotin/streptavidin. As a result, biomolecules containing desthiobiotin are dissociated from streptavidin simply in the presence of buffered solutions of biotin. We offer desthiobiotinTEG phosphoramidite and the corresponding CPG.
Coupling: 12-15 minute coupling time. To maintain label yield, carry out the synthesis DMT-On.
Deprotection: To maintain label yield as a 5' modifier, cleave and deprotect as required by nucleobases and then remove the DMT group. Alternatively, treat column with 10% diethylamine in acetonitrile for 2 minutes at room temperature (2x) to remove cyanoethyl protecting groups and rinse with ACN. At this point, the DMT group may be safely removed without loss of label during deprotection.