Isolation and preservation of cell nuclei for studies on RNA polymerase activity

Abstract

The suitability of saponin for the isolation and of glycerol for the preservation of mammalian cell nuclei has been investigated. The nonionic detergent saponin was found to be a useful cell lytic agent in a procedure for the isolation of nuclei from several mammalian cell types. The RNA polymerase activity of rat liver nuclei was not affected by treatment with saponin or with some other nonionic detergents that were tested. Low concentrations of ionic agents also did not affect the activity of the enzyme though higher concentrations caused lysis of the nuclei. The preservation of structure and enzyme activity in the isolated nuclei was achieved by storage at low temperature in a medium containing 70% glycerol together with a suitable concentration of a divalent metal and phosphate buffer.