Oligonucleotide separation techniques for purification and analysis: What can we learn for today's tasks?

Nucleic acids are the blueprint of life. They are not only the construction plan of the single cell or higher associations of them, but also necessary for function, communication and regulation. Due to the pandemic, the attention shifted in particular to their therapeutic potential as a vaccine. As pharmaceutical oligonucleotides are unique in terms of their stability and application, special delivery systems were also considered. Oligonucleotide production systems can vary and depend on the feasibility, availability, price and intended application. To achieve good purity, reliable results and match the strict specifications in the pharmaceutical industry, the separation of oligonucleotides is always essential. Besides the separation required for production, additional and specifically different separation techniques are needed for analysis to determine if the product complies with the designated specifications. After a short introduction to ribonucleic acids (RNAs), messenger RNA vaccines, and their production and delivery systems, an overview regarding separation techniques will be provided. This not only emphasises electrophoretic separations but also includes spin columns, extractions, precipitations, magnetic nanoparticles and several chromatographic separation principles, such as ion exchange chromatography, ion-pair reversed-phase, size exclusion and affinity.