Reliable liquid reagent handling and rotational release for centrifugal sample-to-answer automation

Most point-of-care applications require onboard storage of liquid reagents such as buffers and stains. The reliable handling and release of these reagents is key to enabling the multiple unit operations on these platforms. We present here a centrifugal buoyancy-driven release mechanism [1], where the balance between a stored aqueous reagent (to protect a lipophilic dissolvable-film (DF)) and an ancillary oil liquid allows for controlled release. At the beginning of the assay protocol, the disc is spun to generate sufficient centrifugal pressure allowing the denser ancillary phase to reliably displace the aqueous phase to thus open the DF, due to stratification of the immiscible phases.