Measurements of biomarkers of platelet activation in Xcoating^TM circuit. (A) No significant changes were detected in soluble P-selectin levels in collected bovine blood at 5 min, 30 min, and 55 min using the Xcoating^TM circuit, with values at each time point falling within ±2 SD of the mean. All measurements are presented as normalized values over the platelet count for each time point. (B) The normalized values for PF4 did not change over time with all values at each timepoint falling within ±2 SD of the mean. (C) Normalized values for GPIIb/IIIa and (D) β-TG did not show any significant changes at 5 min, 30 min, and 55 min, but all values fell within ±2 SD of the mean, indicating minimal intra-variability across technical replicates. (Mean ± SD, P < 0.05, five technical replicates). GPIIb/IIIa: Glycoprotein IIb/IIIa; PF4: Platelet Factor 4; β-TG: β-Thromboglobulin.