Development of RNA/DNA automated extraction and purification device for infectious disease diagnosis

Genetic tests using RNA/DNA are the most accurate for diagnosing infectious diseases and assessing disease susceptibility, including COVID-19. However, manual specimen handling and the risk of secondary infections by medical staff highlight the need for automated equipment. Automation methods, such as bead purification, have limitations with high-viscosity specimens, while column purification requires complex equipment. This study aimed to develop an automated device using the column purification method for safe and reliable infectious disease diagnosis. We compared the yield and purification of three nucleic acid extraction methods (centrifugation, pressurization, and depressurization) and examined the adaptation of the extraction methods to automated device. Furthermore, we examined the feasibility of extracting SARS-CoV-2 RNA from COVID-19 patients and using qPCR analysis to determine whether the extraction method could be used as a clinical analyzer. Results varied with different columns and reagents, but pressurization method was selected for the automated device's RNA/DNA extraction. Using an automated device equipped with a pressurization method, RNA extracted from pharyngeal fluids from COVID-19 patients who had already been diagnosed with SARS-CoV-2 by qRT-PCR again tested positive. These findings demonstrate the device's effectiveness for nucleic acid extraction and virus-targeted diagnostics. Moreover, it holds potential for genetic testing in fields like food and environmental measurements. The automated device addresses specimen handling challenges and provides a reliable tool for infectious disease diagnosis.