Standardizing high-throughput RNA extraction: Modifying commercial kits for improved purity, yield, and efficiency

High-throughput extraction kits are widely use in clinical and preclinical settings to extract nucleic acids from biological samples due to their scalability, repeatability, and reduced labor. However, achieving high nucleic acid yield and purity while maintaining reliability and reproducibility remains challenging in molecular biology labs, partly due to lack of standardized guidelines for nucleic acid extractions and purification. Variations in extraction kits and extraction chemistries often lead to inconsistence results across experiments.

To address this variability, we modified manufacturers' extraction protocols by introducing additional chloroform and ethanol extraction steps. These modifications aimed to optimize RNA purity, yield, and extraction efficiency (EE) using Xeno Internal Positive Control (IPC) spiking as a benchmark. We evaluated the performance of three commercially available magnetic-bead-based RNA extraction kits across six naïve non-human primate (NHP) tissue types: brain, heart, kidney, liver, lung, and spleen, using the KingFisher™ Flex automated extraction platform.

The modified protocols demonstrated significant improvements in RNA purity, yield, and EE across the selected kits. These additional steps enhanced the suitability of extracted RNA for downstream applications, underscoring the importance of considering both kit performance and tissue characteristics in experimental design.

We further assessed the MagMAX™ mirVana™ Total RNA Isolation Kit for its ability to remove interfering nucleic acids, such as plasmid DNA and single-stranded DNA (ssDNA), from adeno-associated viral (AAV) vector preparations. Specifically, we invesigated AAV serotype 8 (AAV8) due to its popularity in use for gene and cell therapies. The kit demonstrated high efficiency, removing ≥98 % of non-encapsidated genomes, plasmid DNA, and other impurities, yielding RNA suitable for downstream applications and removing contaminating DNA that would create a false-positive signal and result in over quantification.

These results emphasize the value of optimized, standardized protocols to improve reproducibility and reliability in RNA extraction workflows, with broad applications in molecular biology, gene therapy, and cell biology research.