The process of actual separation of cells at the end of mitosis is called

The process is called cytokinesis. Mitosis or phase m of nuclear division is a process which consists from a few phases. From first to last these are:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
and the last one is 
5. Cytokinesis. What is different about this phase from all the others is that, even though in the previous phases we have a division of the nucleus, this is the phase in which the cytoplasm and the cell membrane also divide, resulting with two new separate cells.