Project description:To investigate the mechanisms of endotoxin-induced acute kidney injury in mice, we performed Nanopore long-read RNA sequencing on bulk kidney tissues using the direct cDNA sequencing kit (SQK-DCS109) and R9.4.1 flow cells.
Project description:Long-read RNA sequencing enables isoform-resolved transcriptomics, but library preparation introduces systematic biases that shape biological interpretation. We benchmarked Oxford Nanopore’s two protocols—PCR-cDNA and direct RNA—using SKMM2 myeloma cells stimulated with interleukin-6 (IL-6) and ERCC synthetic spike-ins. Direct RNA produced longer, higher-quality reads and more high-confidence isoforms, but showed pronounced 5′ coverage loss. PCR-cDNA yielded shorter fragments with 3′ underrepresentation, detecting more low-abundance transcripts at reduced confidence. Protocol-specific biases had major consequences: differential expression analysis revealed limited overlap in IL-6–responsive genes, and pathway enrichment was broader in direct RNA. At the isoform level, differential transcript usage was almost entirely protocol-specific, with case studies (e.g. RPL22L1, GRB2, RNF220) illustrating concordance and divergence. ERCC controls confirmed these biases as technical rather than biological. Together, our results show that while both methods provide accurate gene-level quantification, transcript-level conclusions depend critically on protocol choice, highlighting the need for careful selection in long-read transcriptomics.
Project description:To evaluate targeted MinION next generation sequencing as a diagnostic method for detection of pathogens in human blood and plasma, human blood or plasma samples were spiked with measured amounts of viruses, bacteria, protozoan parasites or tested pathogen-free as negative controls. Nucleic acid was extracted from samples and PCR amplification performed in multiplex primer pools with a procedure described in ArrayExpress experiment submission ID 18379. The PCR products were used for library preparation. The libraries sequenced on an Oxford Nanopore MinION. The passed reads aligned with a custom reference file to determine the identity of the pathogen in the sample.