Fully integrated dilution series generation on a laboratory centrifuge

We present a novel approach for the fully automated generation of dilution series using a disposable microfluidic cartridge. Fluids are metered, mixed and routed without active valving by defined rotational speed only. As a processing device, a standard lab centrifuge can be used. The dilution ratio can be freely choosen by loading the corresponding volume of sample into the cartridge without the need for changes in the microfluidic layout. Dilution series of Fluorescein in PBS buffer with ratios of 1:3 and 1:5 are shown with each dilution series comprising 5 single dilution steps. Reproducibility was determined by fluorescence measurement.