Prometaphase is the phase in between prophase and metaphase, in mitosis, in eukaryotic somatic cells. Microtubules which have radiated from the two centrosomes located at the opposite poles of the cells invading the nuclear space within it as the nuclear membrane dissolves, this process named open mitosis. This allows the double chromosomes within them to be distributed to the different locations of the cell by the microtubules without restriction.