Mass isolation of calf thymus centrosomes: identification of a specific configuration.

Centrosomes from calf thymocytes were isolated using a simple preparative procedure that provides large yields of free organelles. A comparative study with centrosomes isolated from human cultured lymphoblasts has led to the discovery of important differences in the structure of the two isolates and in their capacity to nucleate microtubules from purified tubulin. The possibility that the centrosomal structure depends upon the growth state of cells is discussed.