Active alignment of microtubules with electric fields.

The direction of translocation of microtubules on a surface coated with kinesin is usually random. Here we demonstrate and quantify the rate at which externally applied electric fields can direct moving microtubules parallel to the field by deflecting their leading end toward the anode. Effects of electric field strength, kinesin surface density, and microtubule translocation speed on the rate of redirection of microtubules were analyzed statistically. Furthermore, we demonstrated that microtubules can be steered in any desired direction via manipulation of externally applied E-fields.