Table I. Motility and chemotaxis parameters in a spatial gradient of cAMP.

Cell type	Cell number	Velocity (µm/min)	Persistence (µm/min-deg)	Roundness (%)
AX2	47	11.32 ± 1.23	4.40 ± 0.80	75.04 ± 3.43
LimC–	14	10.19 ± 1.63	4.22 ± 1.28	74.02 ± 0.31
LimD–	27	8.07 ± 2.47	2.93 ± 1.05	80.22 ± 3.97
LimC–/LimD–	66	7.65 ± 1.86	2.73 ± 0.94	79.51 ± 4.19
Rescue	12	8.96 ± 1.06	3.11 ± 0.77	72.83 ± 5.57

Images were taken at 10× magnification every 30 s. In all cases cells were analyzed for at least 10 min. Persistence is essentially speed divided by the directional change. If an object is not turning, its persistence is the same as its speed. The roundness parameter indicates polarization. Generally, a more polarized cell shape produces less roundness.