Abstract: The present disclosure describes methods for analyzing mRNA poly(A) tail sequences with a high resolution to determine poly(A) tail length and heterogeneity. The method involves digesting an mRNA molecule to liberate a poly(A) tail, preparing a chromatographic sample comprising the mRNA poly(A) tails, preparing a second chromatographic sample comprising a reference sequence comprising a mRNA poly(A) tails having a predetermined length, separating the first and second samples by a chromatography method, which result in one or more chromatograms, and determining a sequence length of the mRNA poly(A) tails by comparing the chromatograms of the first and second samples. Chromatography methods for analyzing the poly(A) tail may include ultraviolet size-exclusion chromatography (SEC UV), ultraviolet ion-pair reversed-phase liquid chromatography (IP RP LC UV), ultra high performance liquid chromatography (UPHLC), and combinations thereof.

Abstract: The present disclosure describes methods, kits, and systems for digesting polyribonucleotides. The method involves selectively forming oligonucleotide (e.g., DNA:RNA or RNA:RNA) duplexes with single-stranded target RNA and then using sequence-specific nucleases that only act on RNA within duplexes to selectively cleave the target RNA into smaller fragments. Additional sequence-specific ribonucleases may be used to provide additional cuts of the target RNA at predetermined sites. By forming duplexes to increase the availability of nucleases that may be applied to cleave the single-stranded target RNA and selectively control where the target RNA is cleaved, the target RNA may be digested into fragments within controllable size ranges that are optimal for polynucletide analysis, such as by liquid chromatography and mass spectrometry.

Abstract: The present disclosure is directed to methods of sample preparation from lipid nanoparticle (LNP)-encapsulated nucleic acids utilizing solid-phase extraction techniques.