Selective kinesin and dynein immobilizaton and electrical microtubule manipulation for bidirectional microtubule motility

We present a method to make microtubules (MTs) glide bidirectionally depending on their polarities in a closed chamber, in which kinesin and dynein are coated on top and bottom glass surfaces, respectively. Once top Au-coated and bottom ITO-coated glass coverslip were assembled to a flow chamber, surface modification and sequential protein injections realized selective dynein and kinesin coatings. Therefore, plus ends of MTs lead on the top dynein/Au-coated surface, and minus ends lead on the bottom kinesin/ITO-coated surface. These gliding MTs were removed one surface and collected to the other surface by applying voltage for controlling MT gliding directions. These fundamental techniques are essential to drive MTs back and forth in a microfluidic system.