Microscopic image of the observation area and representative cell trajectory plots. A: Representative HT-1080 microscopic image of the chamber observation area (2 mm × 1 mm) at time 24 h with an overlay of the tracked cell trajectories. Data from a positive chemotaxis experiment using 10% FCS as attractant (+/-) is shown. Figure 4B shows the corresponding trajectory plot. Figures 4B-D: Representative HT-1080 cell trajectory plots in the time period from 0 to 24 hours. (B) Chemotaxis experiment using 10% FCS as attractant. Cells move in the positive direction of the║-axis, which is by definition the direction of the gradient (+/-). (C) In the negative control, both chambers are filled with FCS-free medium (-/-). Directed cell migration is not visible. (D) In the positive control group, both chambers are filled with FCS 10% (+/+). As in the negative control group, no directed migration can be measured. Cell motility is enhanced. Figures 4E-G: Representative HUVEC trajectory plots in the time period from 0 to 24 hours. (E) Similar to HT-1080, HUVEC also move in the direction of the FCS gradient (+/-). Negative (F, -/-) and positive (G, +/+) controls show no directed migration and a smaller displacement of centre of mass.