Segmented and polarity-marked microtubules are very useful for many different types of in vitro assays. Segmented microtubules are microtubules with a bright seed and dim elongated segments on both ends. Polarity marked microtubules are microtubules with a bright seed and a dim elongated segment only on one end -- the plus end. - [Read Preparation of Segmented and Polarity Marked Microtubules Protocol]