Development of a new cell isolation device FlowMagicTM

Abstract

Isolation of human peripheral blood mononuclear cells (PBMCs) from blood typically involves a density gradient medium during density centrifugation. The problem of increasing red blood cell (RBC) and granulocyte (GRA) contamination during PBMC isolation as the elapsed time after blood collection increases remains unresolved. As a countermeasure against RBC contamination, hemolysis treatment is available; however, these extra steps are laborious, time-consuming, and could introduce artifacts. To overcome this challenge, we developed a novel isolation device, FlowMagic™, which features a proprietary two-layer insert structure designed to prevent RBC and GRA contamination during PBMC isolation from blood. The efficacy of this method was evaluated by isolating PBMCs from donors and analyzing immune cell populations by flow cytometry. Compared to SepMate (median (Q50) = 11.0, interquartile ranges (IQR): 8.8–19.5; p < 0.01) and Lymphoprep methods (Q50 = 9.3, IQR: 6.6–13.5; p < 0.01), FlowMagic™ achieved significantly greater reduction in RBC contamination to below detectable limits (Q50 = 0.0, IQR: 0.0–0.0), with sustained efficacy observed up to 72 hours post-collection. Additionally, the FlowMagic™ method (Q50 = 2.5, IQR: 0.5–3.4, at 48 hours, median = 4.5, IQR: 2.1–10.3, at 72 hours, respectively) significantly reduced GRA contamination compared with the SepMate (Q50 = 12.0, IQR: 7.8–25.5, at 48 hours, Q50 = 27.5, IQR: 12.3–29.0, at 72 hours, respectively; p < 0.01) and Lymphoprep methods (Q50 = 10.5, IQR: 6.9–19.8, at 48 hours, Q50 = 17.5, IQR: 13.3–23.5, at 72 hours, respectively; p < 0.01) at 48 and 72 hours after blood collection. Furthermore, the recovery rates of CD3 +, CD4 +, CD8 +, CD19 +, and CD16/56 + cells in the FlowMagic™-isolated PBMCs (Q50 = 8.6, 5.9, 2.5, 1.3, and 1.9, respectively) were significantly improved compared to those in SepMate- (Q50 = 2.2, 1.5, 0.7, 0.4, and 0.5, respectively; p < 0.01) and Lymphoprep-isolated PBMCs (Q50 = 2.4, 1.5, 0.8, 0.6, and 0.8, respectively; p < 0.01), even at 48 hours after blood collection. These findings suggest that the PBMC isolation method using FlowMagic™ is advantageous in preventing RBC and GRA contamination for research, diagnostic, and clinical applications.