Anaphase

After metaphase is complete, the cell enters anaphase. During anaphase, the microtubules attached to the kinetochores contract, which pulls the sister chromatids apart and toward opposite poles of the cell . At this point, each chromatid is considered a separate chromosome.

Hello..

So, when cells undergo mitosis, they don't just divide their DNA at random and ... Mitosis consists of four basic phases: prophase, metaphase, anaphase, and ... to chromosomes at the kinetochore, a patch of protein found on the centromere 

Anaphase. The shortest stage of mitosis. The centromeres divide, and the sister chromatids of each chromosome are pulled apart - or 'disjoin' - and move to the opposite ends of the cell, pulled by spindle fibres attached to the kinetochore regions.