The mitotic spindle is a highly dynamic molecular machine composed of tubulin, motors and other molecules. It assembles around the chromosomes and distributes the duplicated genome to the daughter cells during mitosis.
Microtubules are unbranched, hollow, sub- microscopic tubules, which form the structural material of cilia, flagella, basal bodies, centrioles and spindle apparatus. They are built up protofilaments, formed of two related proteins, α and β - tubulins.