External Magnetic Stage

One of the most popular applications in digital microfluidics has been to automate assays that rely on magnetic particles – immunoassays, immunoprecipitation, oligonucleotide pull-down, and so on. Briefly in these experiments, droplets are manipulated containing a suspension of particles. When a magnetic field is applied, the particles are pulled to the surface, and the droplet is moved away. The magnetic field is then removed, and the particles suspended in a fresh droplet to continue the assay.

The Sci-Bots External Magnetic Stage features a 1.38 T neodymium magnet bar, mounted to a stainless steel “magnetic lens” that allows simultaneous magnetic particle pulldown from up to eight droplets in parallel (similar to what is described in this paper and shown in this movie). The stage features a high-performance Z-axis stage (similar to the one described in this paper), with state controlled via a custom PCB that is integrated into your MicroDrop protocols through a custom plugin. The system is supported in a rugged, precision-milled 145mm x 160mm x 100mm Delrin chassis. In all, the Sci-Bots External Magnetic Stage comprises everything needed to run the system, including:

• DropBot Extender (can be used alone for other applications)
• Magnetic Stage and Chassis
• Custom PCB Controller
• MicroDrop Plugin
• USB and power cables