A microfluidic system for performing fast, sequential biochemical procedures on the surface of mobile magnetic particles in continuous flow

A rapid, highly versatile microfluidic platform is demonstrated for performing multi-step (bio)reactions on the surface of single magnetic particles in continuous flow. Functionalised magnetic particles were deflected across the width of a reaction chamber along which multiple laminar reagent streams had been generated. As the particles traversed the reagent streams, several operations were performed on their surface including washing, incubation and detection, all within a fraction of the time required for conventional assaying methods. The microfluidic platform was applied to a mouse IgG immunoassay and a DNA hybridisation assay, both involving two washing steps and one reaction step. These continuous flow procedures were performed in less than one minute and could be adapted for many other analytical measurements.