ISOLATION OF NUCLEI FROM MAMMALIAN TISSUES THROUGH THE USE OF TRITON X-100

It has been found that nuclei from a variety of mammlian cell types maintain their structural integrity (at the light microscope level) when exposed to the non-ionic detergent Triton X-100, in the presence of Mg or Ca ions. This observation has led to the development of a simple, rapid, and reproducible method of nuclear isolation. Nuclei isolated by this method contain more than 90% of the deoxyribonucleic acid (DNA) from filtered homogenates and exhibit diphosphopyridine nucleotide (DPN) pyrophosphorylase activity. The isolated nuclei also retain rapidly labeled ribonucleic acid (RNA) after in vivo incorporation of labeled RNA precursors. Free mitotic metaphase figures have been seen in nuclear fractions prepared from tumor cells in the Triton X-100, an observation which suggests that metaphase aggregates could be isolated in quantity with the use of this detergent and appropriate choice of tissue.