The Cobas Eplex System
Nucleic acid extraction from biological samples occurs within the cartridge via lysis, nucleic acid capture onto magnetic beads and release for amplification. A majority of the nucleic acid extraction is processed through traditional microfluidic liquid handling. Once the nucleic acid targets are captured and inhibitors are washed away, the magnetic particles are delivered to the electrowetting environment on the printed circuit board (PCB) and the targets are eluted from the particles and amplified. During hybridization, the single-stranded target DNA binds to a complementary, single-stranded capture probe immobilized on the working gold-plated electrode surface. Single-stranded signal probes (labeled with electrochemically active ferrocenes) bind to specific target sequence/region adjacent to the capture probe. Simultaneous hybridization of target to signal probes and capture probe is detected by alternating current voltammetry (ACV). Each working electrode on the array contains specific capture probes, and sequential analysis of each electrode allows detection of multiple analyte target