Multi-reagents dispensing centrifugal microfluidics for point-of-care testing

Point-of-care testing (POCT) has shown great advantages for public health monitoring in resource-limited settings. However, developing of POCT tools with automated and accurate quantitative dispensing of multiple reagents and samples is challenging. Here, we demonstrate a novel multi-reagents dispensing centrifugal microfluidics (MDCM) that allows rapid and automated dispensing of multiple reagents and samples with high throughput and accuracy. The MDCM was designed with multiple aliquoting units with the hydrophobic valve at different radial positions. All reagents and samples were loaded simultaneously, dispensed in parallel by centrifugation at low speed, and then introduced into the reaction chamber sequentially by centrifugation at high speed. Two MDCM chips are demonstrated, including a uniform concentration generator and a gradient concentration generator. The concentration coefficient of variation (CV) among the independent reaction chambers was lower than 0.56%, and the theoretical quantitative concentration gradient was strongly correlated with the actual concentration gradient (R