Carboxy-C10 (Figure 1) is a 5'-Carboxy-Modifier C10 succinimidyl ester (NHS), which can be useful to attach an active carboxyl group to the 5'-end of an oligonucleotide. A 10-carbon spacer arm separates the carboxyl group from the oligonucleotide, thereby reducing steric interactions between the carboxy group and the oligo itself. Depending on the application, the carboxy group allows the oligo to be labelled with a variety of different moieties, like fluorescent dyes, quenchers, haptens, etc.
Figure 1. Structure of 5'-Carboxy-C10 (R = sequence).
metabion offers Carboxy-C10 as a 5'-modification in its standard DNA portfolio: