Figure 5. Differential deflection of microcantilever arrays with MCF7 spiked into human blood samples.

(a) Top figure shows results from injection of whole blood spiked with MCF7 cells, whereas (c) lower figure shows data from injection of blood without plasma where blood was first spiked with MCF7 or MCF10A cells followed by plasma removal. The system was first equilibrated by injection of blood samples free from cell lines, followed by injection of samples containing 25, 50 or 100 cells/mL. The control represents the response of a negative analogue of peptide 18-4 to ∼100 cells mL⁻¹ spiked samples. Figures (b) and (d) show the average deflection of peptide 18-4 coated cantilevers in both, whole blood and blood without plasma, respectively, based on three individual studies performed under the same conditions. The error bars indicate corresponding standard deviations.