C7-Amino (Figure 1) is useful to incorporate a primary amino group at the 3’ terminus of an oligonucleotide. A 7-carbon spacer arm separates the amino group from the oligonucleotide, thereby reducing steric interactions between the amino-moiety and the oligo itself. This modification allows the conjugation of the oligonucleotide with a variety of different moieties, like fluorescent dyes, quenchers, haptens, etc.
Figure 1. Structure of 3'-C7-Amino (R = sequence).
metabion offers C7-Amino as a modification in its standard DNA portfolio: