Genotyping of Multiple Clinical Samples with a Combined Direct PCR and Magnetic Lateral Flow Assay

Developing a sensitive, low-cost, and easy-to-use point-of-care testing system for genotyping is important for informing treatment decisions and predicting the risk of underlying diseases. Conventional methods normally require complex operational procedures as well as expensive and sophisticated instruments. Here, we report a general approach that enables us to detect the genotype of multiple sample types directly without DNA purification. Moreover, the PCR results can be further quantitatively analyzed based on a magnetic lateral flow assay (MLFA) system, which avoids multiple steps needed for conventional nucleic acid biosensors. As a demonstration, we show that three genotypes of aldehyde dehydrogenase 2 (ALDH2) can be identified using a small volume of sample with an accuracy of 100% and a sensitivity of 1.0 x 10² cells/µL, which are better than those of the gold standard methods. We believe that the direct PCR-MLFA system represents a significant advance toward the development of portable, sensitive biomedical platforms.