Combination of a robotic solution pipetting device with a centrifugal molecular diagnostic platform for fully automatic respiratory infectious virus detection from nasopharyngeal swab samples

Abstract

A novel molecular diagnostic platform is presented that enables complete automation for the genetic analysis of respiratory infectious virus including the solution loading, RNA purification, reverse transcription-loop-mediated isothermal amplification (RT-LAMP), and real-time fluorescence detection. The overall structure consists of three parts: an integrated centrifugal microfluidic disc, a point-of-care (POC) genetic analyzer, and a robotic solution pipetting device. The integrated centrifugal microfluidic disc was designed to treat up to four samples simultaneously, with the capacity to detect seven targets in a single run. Additionally, a solution-loading cartridge is combined on the disc, facilitating the insertion of a nasopharyngeal swab sample as well as the storage and aliquoting of the washing solution, the elution solution, and the RT-LAMP master mix. The POC genetic analyzer is composed of a spinning motor for the automatic release of solutions, a couple of peltier heaters for gene amplification, a miniaturized fluorescence detector to generate an amplification curve, and an LED screen for displaying the experimental parameters and the diagnostic results. Importantly, we also integrate a robotic solution pipetting device with the POC genetic analyzer so that the designated solution can be loaded into the solution-loading cartridge without need of manual operation. Five targets (influenza A subtypes H1N1 and H3N2, influenza B, and SARS-CoV-2 (orf1ab and S gene)) of four samples were identified in 1.5 hr on a single device with a sample-in-answer-out manner.