Using ddPCR Technology To Characterize The Poly(A) Tail Content In mRNA Products

Therapeutic mRNA is in vitro transcribed mRNA that is delivered to a target cell where the cell translates that mRNA into a protein to effect a therapeutic action. The benefits of using mRNA as a therapeutic were demonstrated during the COVID pandemic. Native and therapeutic mRNA molecules have a 3’ polyadenylation tract, known as a poly(A) tail. This poly(A) tail serves to stabilize the mRNA molecule and facilitate successful protein translation.

The importance of this poly(A) tail is recognized by the United States Pharmacopeia (USP), which recommends characterizing 3’ poly(A) tail length and integrity by ion-pair reverse-phase high-performance liquid chromatography (IP-RP-HPLC). However, a 2023 peer review publication demonstrates the use of Droplet Digital™ PCR (ddPCR™) to characterize poly(A) tail content of mRNA samples, thus demonstrating an orthogonal or alternative method to help ensure the quality and consistency of mRNA products.