New Microfluidic System Provides Automated Alternative To Ficoll (R) For Leukocyte Isolation

Abstract Despite its limitations, Ficoll® has remained the primary method of leukocyte isolation for decades due to a lack of viable alternatives. To address this, MicroMedicine has developed SorterraTM, an automated microfluidic system that enables highly consistent label-free white blood cell separation and concentration. In a comparative study, Sorterra recovered 25% more viable lymphocytes than Ficoll, 88 ± 7% and 69 ± 13%, respectively (n=48). Sorterra retained <0.01% red blood cells (RBCs) and <0.1% platelets, resulting in a highly pure leukocyte isolate, while Ficoll retained <0.01% RBCs and 8% platelets. Sorterra also demonstrated more consistent performance across operators than Ficoll. Sorterra and Ficoll isolates were assessed for B cell and T cell functionality. To assess B cells, the isolates were stimulated with R848 and IL-2 (n=9), and total IgG and IgM secretion were evaluated with ELISpot. Secretion from Sorterra and Ficoll isolates was shown to be equivalent using distribution free resampling analysis. To assess T cell functionality, negatively selected T cells from Sorterra and Ficoll isolates were activated with CD3/28 beads and expanded with IL-2 (n=12). The isolates displayed similar T cell activation (89±4% vs. 88±5% CD25+/CD69+), proliferation, and T cell phenotypes (Tn TCM, TEM, TEFF) at 7 and 10 days post activation. Compared to Ficoll, Sorterra enables rapid, automated isolation of leukocytes, consistently yielding more lymphocytes with negligible RBCs and platelet contamination while maintaining T cell and B cell function. By minimizing operator variability, Sorterra has the potential to transform cell separation by automating an outdated, variable, and labor-intensive process.