FRACTIONATION OF MAMMALIAN LIVER CELLS BY DIFFERENTIAL CENTRIFUGATION : I. PROBLEMS, METHODS, AND PREPARATION OF EXTRACT.

1. Materials and technical procedures involved in the preparation of liver suspensions have been described and discussed. 2. Liver extracts prepared by the present method appear to contain almost exclusively elements of cytoplasmic origin and can be considered to represent, on a large scale, the cytoplasm of liver cells.