An Innovative Binding-Protein-Based dsRNA Extraction Method: Comparison of Cost-Effectiveness of Virus Detection Methods Using High-Throughput Sequencing.

Viral diseases represent a threat to global food production. Managing the impact of viruses on crop production requires the ability to monitor viruses, study their ecology and anticipate outbreaks. Double-stranded RNA (dsRNA) sequencing is a well-established and reliable method of detecting viruses and studying virome-host interactions and ecology. Compared to total RNA extraction, dsRNA extraction eliminates the majority of host RNAs, improving the recovery of viral RNAs. In this study, we developed and evaluated a novel dsRNA extraction method for high-throughput sequencing (HTS) applications based on the Flock House virus (FHV) B2 protein (B2-based method), and compared its performance with that of established cellulose-based and DRB4-based methods (commercial kit), as well as total RNA extraction techniques. The electrostatic properties of B2 have been instrumental in developing a bead-free and resin-free dsRNA extraction method. The B2-based method demonstrated high viral read recovery, achieving proportions exceeding 20% in most samples, and provided better dsRNA purity with less low weight molecule co-extracted RNA than the DRB4-based method and cellulose-based methods. Despite producing overall fewer total reads than the DRB4-based method, the B2-based enrichment for viral-derived dsRNA was better, with a higher percentage of viral reads, making it effective in virome profiling. Furthermore, it had an excellent detection specificity (0.97) and a good detection sensitivity (0.71), minimising false positives and false negatives. In addition, the B2-based method proved to be highly cost-effective, with a per-reaction cost of $4.47, compared to $35.34 for the DRB4-based method. This method offers a practical solution for laboratories with limited resources or for large-scale sampling for viral ecology studies. Future improvements to the B2-based method should focus on optimising sensitivity to Vitivirus species and developing scalable, automated workflows for high-throughput viral detection.