Morpholino oligos, also known as phosphorodiamidate morpholino oligomers (PMOs), are short single-stranded DNA analogs containing the backbone of morpholine rings and phosphorodiamidate linkages that replace the 2’-deoxyribonucleoside and phosphate linkages of canonical DNA, respectively. PMO binds to the complementary sequence of target messenger RNA (mRNA) through Watson-Crick base pairing and blocks mRNA translation through sequence-specific steric blocking. Oligo synthesis Morpholinos are six-membered rings which may provide higher conformational rigidity when incorporated into an oligonucleotide backbone. In addition, the morpholine rings are not recognized by immune cells. PMOs are resistant to a variety of enzymes both in vitro and in vivo and elicit low immunogenicity in mammalian models. Due to their specificity, solubility, low toxicity, stability, and high efficiency, PMOs have been researched extensively in oligonucleotide therapeutics as potential steric blocking agents for the treatment of various genetic disorders.