Phosphoramidite used to incorporate a C-5 propyne modified dC either internally or at the 5' end of an oligonucleotide.

Phosphoramidite replacement for dC that enhances base-pairing.

Phosphoramidite for incorporation of an (otherwise unmodified) reverse (5’ to 3’) dC nucleobase within an oligonucleotide.

Phosphoramidite used to incorporate a deoxycytidine into an oligonucleotide, with an ethylated backbone.