Table 1.

ECM proteins used in this study

ECM	Stock concentration	Final concentration	Source
Poly-D-lysine	1 mg/ml	50 μg/ml	Sigma P7280
Type I collagen	2.5 mg/ml	100 μg/ml	Sigma C9791
Fibronectin	1 mg/ml	20 μg/ml	Sigma F1141
Vitronectin	50 μg/ml	2 μg/ml	Sigma V8379
Laminin	0.9 mg/ml	10 μg/ml	Invitrogen 23017-015

ECM proteins were added at the indicated final concentration in a volume of 500 μl, and left overnight at 4°C.