Detection of Locked Nucleic Acid and 2'-O-Methoxyethyl Gapmers from Mouse Samples Using ELISA

Antisense oligonucleotide (ASO)-mediated therapy is promising for the treatment of a variety of genetic disorders, as primarily seen for Duchenne muscular dystrophy. As more ASOs advance in therapeutic development and enter clinical trials, it becomes necessary to have a means of quantifying their amounts in biological samples post-treatment. This information will be valuable for evaluating the safety and pharmacokinetic profiles of ASOs, and also in deciding how the efficacy of these drugs can be improved. Gapmers are a class of ASOs characterized by having a central DNA segment that is surrounded by chemically modified nucleotides on both ends. While methods to quantify other ASOs, such as phosphorodiamidate morpholino oligomers (PMOs), have been extensively used in in vivo studies, the quantification of gapmers has been more limited. Here, we describe a sensitive enzyme-linked immunosorbent assay (ELISA)-based protocol that can be used to quantify the levels of locked nucleic acid (LNA) and 2'-O-methoxyethyl (2'-MOE) gapmers in mouse muscle tissue.