 In cell biology, the spindal apparatus or mitotic spindle refers to the sinus skeletal structure of eukaryotic cells that forms during cell division to separate sister chromatids between daughter cells. It is referred to as the mitotic spindle during mitosis, a process that produces genetically identical daughter cells, or the mitotic spindle during mitosis, a process that produces gametes with half the number of chromosomes of the parent cell. Besides chromosomes, the spindle apparatus is composed of hundreds of proteins. Cerebral tubules comprise the most abundant components of the machinery.