Plots of the Number of Detected Cells against the Number of Spiked Cells in the Spike-in Experiments.

<p>Cultured tumor cells (SK-BR-3 (breast), PC-9 (non-small cell lung), PC-14 (non-small cell lung), H69 (small cell lung), and SBC-3 (small cell lung)) were separately spiked, in numbers of 10, 100, and 1000, into 3 mL of blood obtained from healthy donors. After enrichment of mononucleated cells from the blood, the cells were entrapped in microwells, followed by immunofluorescent staining with DAPI, chromophore conjugated anti-CK mAb, and anti-CD45 mAb. Then, fluorescent images of the entire area of the microwell array were captured, and the numbers of tumor cells were measured (solid circles). For PC-14, H69, and SBC-3, a further staining protocol, using Alexa Fluor 488 conjugated secondary antibody, was applied for amplification of the weak CK signal (diamonds). The circles and diamonds represent individual data points. The straight lines are the linear fittings, with their slopes and correlation coefficients (R²) given on the plots. Dotted lines represent the function y = x. The plots of spiked tumor cell numbers from 0 to 100 are magnified for easier viewing (logarithmic axes).