A digital microfluidic platform coupled with colorimetric loop-mediated isothermal amplification for on-site visual diagnosis of multiple diseases
Mei Xie, Tianlan Chen, Zongwei Cai, Bo Lei, Dong Cheng
Abstract
copies per μl for each target, exhibiting comparable sensitivity to the conventional LAMP assay but was more efficient. The sensitivity was also competitive with that of microfluidic-based LAMP assays using other POCT devices such as centrifugal discs regarding the detection of the same targets. Moreover, the proposed device possessed a simple chip structure and high flexibility to integrate multiplex analysis, which was beneficial for further widespread use in POCT. The practicability of the DMF-LAMP assay was verified by the testing of field shrimp. The result of the DMF-LAMP assay indicated a good agreement with the qPCR method, with Cohen's kappa values ranging from 0.91 to 1.00 depending on different targets. For the first time, an image processing method was established based on RGB analysis under different lighting conditions, and a universally adaptable positive threshold was determined regardless of lighting conditions. Paired with a smartphone, the objective analytical method was facile to implement in the field. Moreover, the DMF-LAMP system is easy to extend for a broad range of bioassays, with the advantages of low-cost, rapid detection, ease of use, good sensitivity, and easy readout.