The recent emergence of mRNA-based vaccines and therapies has made clear the need for reliable analytical methods that can successfully identify, characterize, and quantify mRNA. This chemical instability demands a deeper understanding of the mechanisms by which mRNA degrades, which can inform the development of formulations, manufacturing methods and storage conditions that maintain the desired biological activity for patients. This application note reports data obtained using the PerkinElmer LC 300 HPLC System with a photodiode array (PDA) detector to analyze mRNA samples produced via in vitro transcription (IVT) using an ion pairing reversed phase assay. Additionally, stressed stability experiments were used to investigate the possibility of using HPLC methods to assess mRNA degradation over time, which would be invaluable in mRNA formulation and process development.