Fig. 2.
(A) Device proof-of-principle studies were conducted using PC3 cells spiked into whole blood at 1,000 cells/mL and processed with a small version of the HB-Chip (Fig. S4, channel height 70 μm, α = 0.43) and a flat-walled device (channel height 100 μm). Capture efficiency is shown for both devices in addition to IgG controls. (B) Relative capture efficiency for head to head comparisons run between the full-sized HB-Chip (channel height 50 μm, α = 0.8) and the silicon CTC-Chip (17). For the data in (B), a single preparation of blood was spiked with PC3 cells at a concentration of 500 cells/mL, divided into equal parts and processed on both platforms. Due to slight errors in spiking concentration, the HB-Chip capture efficiency was determined to be greater than 100% (112.4% ± 1.8%, n = 4). Consequently, the comparison data is normalized against the HB-Chip. (C) Variations in device chamber height showed a minimal impact on capture efficiency, until the chamber height was increased threefold. (D) Variability in device performance is shown for four independent experiments, each with different spiking concentrations of PC3 cells in blood. (E) Micrograph of spiked cancer cells captured on the HB-Chip, representative of capture cell viability (LIVE/DEAD). (Scale bar: 40 μm). (F) Micrograph of spiked cells captured on the herringbone chip and subsequently cultured on the device for 21 d. (G) On-chip FISH of captured LNCaP cells with nuclei stained with DAPI, CEPX (green) and AR gene locus (red). (H) Micrograph of a fluorescently labeled PC3 cell captured on the HB-Chip (top) and subsequent micrograph taken of the same cell stained with H and E. (Scale bar: 10 μm).