Purification of Tetrahymena nuclei by sedimentation at unit gravity.

This protocol provides a method for purification of Tetrahymena nuclei using sedimentation at unit gravity. It is useful for applications where purity of micro- and macronuclei is required beyond that which is typically achieved by differential sedimentation alone. When differential sedimentation is followed by sedimentation at unit gravity, micro- and macronuclei can be purified to virtual homogeneity. This method also permits the purification of homogeneous populations of developing new macronuclei (anlagen) and distinct classes of micronuclei from various stages of conjugation.