Fig. 3.
The ability of each device to concentrate flow was tested by flowing yeast cells at a density of 1 × 108 cells/ml through the device for 30 seconds, stopping flow, and allowing cells to settle for 60 seconds. (A) Counting cells collected at positions P1-P6 shows that cells preferentially collect in the vestibules (green), especially towards the outer edge of the vestibule where flow is slowest. The 90° device performs best, enriching the cell concentration seven-fold over other parts of the same device. By ANOVA followed by Tukey's HSD the circular vestibule positions contained statistically significantly more cells (all p < 0.0059) while the 90° bent design collects more cells than either the straight or angled design (all p < 6.7 × 10−7). In the 90° device the P1-P3 positions collect significantly more cells than positions P4-P6 (p < 0.008). (B) Stage positions where cells were counted. Positions P1-P3 are within the circular viewing areas and positions P4-P6 are within the straight channels. The arrow indicates the direction of flow.