TABLE 1.

Improvement of the chemotropic assay by the newly designed 3D printed device.

Dish as reaction chamber – Probable error sources	3D printed device as reaction chamber -Standardized procedure
Exact parallel wells for signal application must be drawn by hand to allow uniformity and reproducibility of gradient formation	3D printed combs and comb positioning slots allow the exact reproduction of uniform signal gradients
Evaluation line centering the two wells is drawn by hand	Positioning notches allow exact centering of evaluation line in between the two wells
Microscope tables are not optimized in holding round plates making the exact positioning of the evaluation line difficult	3D printed frame fits on standard microscope slides, allowing the exact and easy positioning of the evaluation line
Dishes are not optimized for light microscopy thus complicating documentation	The microscope slide as basis simplifies documentation and allows simultaneously usage of fluorescent markers and labeled proteins