This protocol describes a method for microinjecting proteins into the nucleus or cytoplasm of adherent cells. Microinjection equipment can be obtained from a number of suppliers; this protocol has been used with the Narishige IM-200 air pressure regulator and the Leitz micromanipulator. Using this system, it is possible to microinject a constant volume within a 50% difference among cells. - [Read Microinjection of Protein Samples Protocol]
Tubulin is polymerized into microtubules by incubating tubulin at 37°C with GTP. A nucleation seed is added when the purpose is to assay microtubule elongation. Tubulin can also be polymerized for the purposes of recycling the tubulin or labeling the microtubules with fluorescently labeled tubulin. Based on the protocol by Timothy Mitchison of Harvard University.