Vibration-Assisted Magnetic (VibroMag) Cell Separation for Robotic Liquid Handling Platforms

Cell separation is a critical step in many assays in biomedical research, diagnostics, and drug development. Here, we developed VibroMag, a vibration-assisted magnetic cell separation technology specifically designed for automated processing of standard microwell plates using robotic liquid handling platforms. VibroMag utilizes alternating-polarity magnetic fields to retain magnetically labeled cells in the center of the flat-bottom microwells. Rotational agitation from an integrated plate shaker disperses unlabeled contaminant cells into the supernatant, like gold panning. Efficient supernatant extraction is enabled by pipet aspiration at specific locations. Repeated cycling of this process further enhanced the purity of the resulting cell sample. VibroMag demonstrated superior cell separation performance compared to manual methods and available solutions for robotic liquid handling platforms. Specifically, VibroMag achieved 91% purity with 64% recovery for samples at a 1:5 target-to-background cell ratio and maintained robust performance with 78% purity with 44% recovery at a more challenging 1:30 ratio. Notably, VibroMag excelled at handling precious samples containing low cell numbers, achieving 96% purity with 63% recovery for 10,000-cell samples and 94% purity with 56% recovery for 1000-cell samples. Additionally, the use of flat-bottom microwell plates allows immediate postseparation microscopy analysis without additional pipetting steps. The combination of seamless integration into automated workflows, superior separation performance, and compatibility with downstream analyses highlights the broad utility of VibroMag in high-throughput cellular analysis.