A scalable and cost-efficient rRNA depletion approach to enrich RNAs for molecular biology investigations

Transcriptomics analyses play pivotal roles in understanding the complex regulatory networks that govern cellular processes. The abundance of rRNAs, which account for 80-90% of total RNA in eukaryotes, limits the detection and investigation of other transcripts. While mRNAs and long non-coding RNAs have polyA(+) tails that are often used for positive selection, investigations of polyA(-) RNAs, such as circular RNAs, histone mRNAs, and small RNAs, typically require the removal of the abundant rRNAs for enrichment. Current approaches to deplete rRNAs for downstream molecular biology investigations are hampered by restrictive RNA input masses and high cost. To address these challenges, we developed rRNA Removal by RNase H (rRRR), a method to efficiently deplete rRNA from a wide range of human, mouse, and rat RNA inputs and qualities at a cost 10-20-fold cheaper than other approaches. We employed probe-based hybridization and enzymatic digestion to selectively target and remove rRNA molecules while preserving the integrity of non-rRNA transcripts. Comparison between rRRR to two commercially available approaches found that they had similar efficiencies at depleting rRNAs and comparable off-target effects. Our developed method provides researchers with a valuable tool for investigating gene expression and regulatory mechanisms across a wide range of biological systems at an affordable price that increases the accessibility for researchers to enter the field, ultimately advancing our understanding of cellular processes.