Fig. 3: Comparison of CTC circulatory kinetics to SCLC cell line.

a Schematic demonstrating the bolus cell-injection experiment configuration. A short segment of tubing filled with approximately 40 µL of blood or saline containing 25,000 cells of either SCLC cell line, dissociated primary tumor cells, or dissociated liver metastatic tumor cells is added to the blood return line at the beginning of the experiment for a direct injection of its contents into the circulation within approximately 1 min. Clearance kinetics plots representing the real-time concentration (b) and the normalized concentration to the initial (first 10 min) detected concentration (c). For each group, n = 3 biologically independent experiments. Data are presented as mean ± standard deviation. d Schematic demonstrating the slow cell-line injection experiment configuration. A second peristaltic pump is used to slowly infuse cell-containing saline into the circulation at a flow rate of 2−3 µL/min, with total injected cells mimicking that of the CTC blood exchange experiments. e Cumulative injection (blue) and detection (orange) cell counts over time. f Detection fraction plot representing the average fraction of total detected cells to the total injected cells in the last 30, 45, and 60 min of five blood-exchange experiments and four slow-injection experiments. N = 5 biologically independent blood exchange experiments and n = 4 biologically independent slow injection experiments. All values are represented as mean ± standard deviation. (*p < 0.05 (p = 0.016), two-sided Mann−Whitney−Wilcoxon non-parametric test).