The electrotaxis of T98G U-251MG glioblastoma cells in dependence of extracellular calcium by varying concentration of calcium chelators, EDTA and EGTA. (a) The electrotaxis directedness; (b) The electrotaxis speed; † indicate the electrotaxis groups tested against those without EF stimulation; All groups are statistically compared to controls in cell culture media with 10% FBS; n.s. indicates not significant; **** indicate P