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 set-tings. 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 con-centration 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-2 = 0.9938). We have successfully applied the MDCM to loop-mediated isothermal amplification (LAMP)-based nucleic acid detection for multiple infectious pathogens and antimi-crobial susceptibility testing (AST) for kanamycin sulfate against E. coli. To further extend the applications, the MDCM has also been applied to bicinchoninic acid (BCA) protein assays with online calibration, reducing the detection time from 2 h to 10 min with a twenty-fold reduction in reagent consumption. These results indicated that the MDCM is a high potential platform for POCT.

Automated summary

MDCM technology allows rapid and accurate dispensing of multiple reagents and samples, making it a high-potential platform for POCT.