Fig. 2: Schematics and CBC measurements from in vitro, single-pass experiments from healthy donor whole blood and healthy donor whole blood spiked with leukemic cells.
From: Ultra-low extracorporeal volume microfluidic leukapheresis is safe and effective in a rat model
a Schematic showing how the CIF channels operate. As whole blood enters a CIF element, smaller cells (e.g., RBC and PLT) exit through the gaps i, while larger cells (e.g., WBC) remain in the central retentate channel. b Schematic showing the assembly of an 8-element CIF device. As whole blood enters the input port of the device layer (top right), the blood is separated into 8 parallel CIF elements. Each element’s filtrate is merged and exits from the filtrate output port. WBC in the retentate exit vertically into a collecting top layer and are removed from the retentate output port. c Photograph of a blood-filled CIF device (ruler shown in mm). d, e Collection efficiency data highlights CIF’s ability to separate large cells. RBC and PLT loss are kept to <15%, while large WBCs such as MON and EOS are collected up to an efficiency of ~85%. f The concentration ratio of all designs was significantly higher for WBC than RBC and PLT, with the RBC concentration ratio being close to 1 across all designs. g Among WBC subtypes, EOS and MON exhibited the highest concentration ratios across all designs, followed by PMN. LYM, due to their small size, were least concentrated. h Images of fluorescently labeled MV-4−11 cells spiked into whole blood flowing within the device. Note how most leukemic cells are located within the retentate channel with little to none in the filtrate channels. i, j Both designs were able to effectively concentrate (i, p = 0.0056) and remove (j, p = 0.0007) MV-4−11 leukemic cells from whole blood, with Design 2 being more efficient than Design 4. Data shown as mean ± s.e.m. n = 5 for both healthy and MV-4−11 spiked blood data. Scale bar = 100 µm; wl=width of the fluid lamina, Qr(i)=retentate channel flow, Qgap(i)=filtration gap flow. Data analyzed by (d–g) 2-way RM ANOVA with Tukey’s multiple comparison test or (i, j) 2-tailed paired t-test. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.
