Summary
Researchers at UCLA have designed a disposable system that allows the automated delivery and retrieval of micro-liter sized liquid sample reagents to and from a digital microfluidic chip.
Background
Current systems used to perform sample preparations that integrate with digital microfluidics use liquid valves, rotary valves, or small volume injection loops that are expensive and often require a large apparatus to operate. Other digital microfluidic systems require operators to directly pipette sample reagents into the platform which can incorporate human error and the potential exposure to hazardous chemicals. In order for automated and consistent benchtop chemical synthesis using digital microfluidics to exist, a compact and inexpensive system must be able to interface with the external environment to allow efficient chemical delivery and retrieval.
Innovation
Researchers from UCLA's Department of Molecular and Medical Pharmacology have developed a system for interfacing digital microfluidic chips with external vials for the delivery and retrieval of liquid reagents. The system is capable of preparing and delivering multiple reagents of specific volumes less than 20 μL to the digital microfluidic chip. The digital microfluidic chip can manipulate the discrete droplets of reagents using electric fields to initiate various chemical reactions. The novel interface system can then retrieve and purify the samples, all in a software-controlled automated fashion that eliminates human-induced error. The automated external vial system prevents cross-contamination of reagents and removes the need for manual interfacing (e.g. pipetting) for sample preparation, loading, and collection. Finally, this interface design conveniently allows for disposable cassettes comprised of inexpensive materials.
Applications
Advantages
State Of Development
A working prototype has been developed and is currently being used for experiments in radiochemistry for PET probe synthesis.