Purification of Nucleoprotein Particles by Elution Preparative Gel Electrophoresis

摘要

A preparative elution gel electrophoresis technique is described for ultrapurification of nucleosomes, dimers, and other nucleoprotein macromolecules. The apparatus can accommodate 10 to 20 mg of sample and multiple runs can be obtained from one polyacrylamide gel. The eluate is recovered using an ordinary fraction collector and the sample distribution is measured by an in-line uv monitor. The apparatus has been used to further purify nucleosomes prepared by several different methods. Nucleosome core particles containing precise DNA lengths (146 +- 0.5 bp) have been obtained by this method for crystallization. Nucleosomes containing specific longer DNA lengths, such as 168 bp and 175 bp, or specific labels have also been obtained for biophysical studies. The ease of use and versatility of the system makes it an attractive method for obtaining the homogeneous samples required for reproducible biophysical studies of the nucleoprotein constituents of chromatin as well as other similar macromolecules. 13 refs., 4 figs. (ERA citation 12:001891)