A Rapid and Simple Method for Purification of Nucleic Acids on Porous Membranes: Simulation vs. Experiment

Paper-based microfluidic systems have emerged as one of the most promising technologies for developing point-of-care diagnostic platforms (POCT) for detecting and monitoring various diseases. Saliva is a non-invasive biofluid easily collected, transported, and stored. Due to its accessibility and connection to systemic diseases, saliva is one of the best candidates for medical advancement at the point of care, where people can easily monitor their health. However, saliva is a complex mixture of DNA, RNA, proteins, exosomes, and electrolytes. Thus, nucleic acid separation from the salivary components is essential for PCR applications. Paper membranes are a highly porous and foldable structure capable of transporting fluids without pumps and sophisticated systems. The current work presents an insight into simulations for nucleic acid extraction on three types of porous paper membranes for use in point-of-care devices. The flow fluid model is solved on a COMSOL Multiphysics 5.3 free version platform, and the results are compared with experimental assays. The results show that pore uniformity, wet strength, porosity, and functional groups of MF1™ and Fusion 5™ paper membranes are vital parameters affecting nucleic acid extraction and PCR amplification efficiency.