nuclei can be isolated from the eggs and embryos of the sea urchin by a four step method : ( 1 ) washing with dextrose solution until the cells become weak , ( 2 ) cytolysis in 0.002 m mg ( ++ ) solution , ( 3 ) homogenization of the cytolyzed cells by agitation , and ( 4 ) separation of the nuclei from the rest of the homogenate by centrifugation on a layered sucrose gradient .
C1536403
cytolysis
C0007634
cells