A Sensitive Chemotaxis Assay Using a Novel Microfluidic Device
Figure 2
Assessment of cell migration in microfluidic devices. Cells were plated in the central lower well of a microfluidic device, with 50 ng/mL PDGF in SMC medium placed in the left lower well and SMC medium alone placed in the right lower well, followed by incubation at 37°C for 48 h. (a, b) Phase contrast image of cell chemotaxis from the central channel in the direction of the 50 ng/mL PDGF in the left channel; the images are split along the channel between the sink and source wells so that the full length of the channel can be shown at a magnification sufficient to permit cellular resolution. (c, d) Phase contrast image of cell chemokinesis from the central channel in the direction of SMC medium only. (e, f) Low-power fluorescence image of the left (e) or right; (f) channel at 48 h after staining with Hoechst 33342. (g) High-power fluorescence image of the left channel in panel (e); the black square without cells near the right-hand side of the image (asterisk) is a structural post that marks the start point for the migration. (h) Example of the migration analysis. A vertical red line denotes the start point; the distance from the start point to the center of each cell nucleus is measured, and the sum of all these individual measurements becomes the total migration distance using Matlab.
