Bshara-Corson, S., Vukovic, L., Verhagen, A., Tiemann, T., Murray, C. “ Rare Cell Purification Using Ferrologix’s Digital Magnetic Sorting” Annual Conference of the Society for Laboratory Automation and Screening. February 6, 2022. Boston, MA, USA.
Rare cells such as γδ T cells are a unique subpopulation of T cells that have both innate and adaptive properties that are an area of focus for novel immunotherapies and immunological research. Representing only 1-5% of cells in peripheral blood mononuclear cells (PBMCs), cell purification of these cells is challenging for methods such as in-vitro expansion, flow cytometry, or proteomic/genomic analysis.
While magnetic cell sorting is the gold standard for target cell enrichment, traditional magnetic sorting methods struggle to deliver sufficient purities and yields when targeting rare cell populations. Ferrologix’s core technology, Digital Magnetic Sorting, (aka ratcheting cytometry) consists of a benchtop system that accepts cartridges containing ferromagnetic microstructure arrays which can be used to precisely pilot and filter magnetically tagged cells in a quantitative, highly parallelized manner. The ferromagnetic microstructure arrays pixelate bulk magnetic fields into high-intensity microscopic fields on the length scale of an individual cell. Utilizing micromagnetic arrays with gradient pitch allows immunomagnetically labeled cells to be quantitatively separated based on their bound magnetic content. In the same way flow cytometry “gates” cells based on light intensity, the Ferrologix platform gates cells based on magnetic intensity which enables substantially higher rare cell enrichment capabilities as highly magnetic target cells can be differentiated from a weakly labeled off-target background.
Using commercially available positive isolation kits, magnetic beads can be removed from cells so they can be used in downstream assays. In a split-sample comparison study targeting γδ T cells under positive selection, the Ferrologix system demonstrated purities of 87.9±4.5% compared to traditional cell purification methods using magnetic columns or bulk magnets which delivered 9.9±3.3% and 72.1±1.7% respectively. Ferrologix’s Digital Magnetic Sorting has been able to achieve superior enrichment in targeting rare cell populations even when using small volumes < 250ul and with greater cell recovery compared to other methods. Ferrologix’s platform represents a novel and disruptive new cell sorting technology that can be seamlessly integrated into laboratory automation workflows.