Paper capillary electrophoresis for quantitative separation of viral double-stranded RNA

Abstract

A global risk of viral disease outbreaks emphasizes the importance of rapid and simple diagnostic techniques for infectious diseases. Conventional reverse transcription nucleic acid amplification (RT-PCR) as gold standard has limitations in detection of rapidly spreading viral mutants due to sequence requirement, motivating a universal biomarker. Viral double-stranded RNA (dsRNA), a byproduct of viral replication, enables rapid diagnosis of viral infection without prior information of virus. Recently, antibody-based techniques targeting the long double helix structure of viral dsRNA have been studied for viral dsRNA detection. However, time-consuming processes such as antibody incubation and RNA recognition are still required. Here we report a paper capillary electrophoresis chip for quantitative separation of long viral dsRNA from RNA mixtures. RNA molecules pass through the micro-/nano- cellulose pores inside the paper according to their charge to mass ratio under high electric field. Fluorophore tagged poly I:C, which mimics long viral dsRNA, was separated from a RNA mixture using paper-based electrophoresis, and quantitatively detected within the range of viral infection concentration.