Pan-O-GlcNAc antibodies that recognize the O-GlcNAc modification largely irrespective of the modified proteins identity are commonly used. These include RL2, an IgG antibody raised against O-GlcNAcylated nuclear pore complex proteins, and CTD110.6, an IgM antibody raised against an immunogenic peptide with a single serine O-GlcNAc modification. Other O'-GlcNAc-specific antibodies have been reported and demonstrated to have some dependence on the identity of the modified protein.