Preparation of Ribonucleoprotein-Enriched Nucleoplasmic Extracts from Drosophila Cells

Abstract

Here we describe how to prepare nucleoplasmic extracts from suspension cultures of Drosophila S2 (Schneider Line 2) cells. Harvested cells are washed in phosphate-buffered saline supplemented with MgCl₂, resuspended in hypotonic buffer, and homogenized. Nuclei are isolated by centrifugation and then sonicated. The nuclear sonicate is placed on a 30% sucrose cushion and sedimented. The soluble nuclear ribonucleoprotein (RNP) complexes remain in the supernatant and the nuclear membrane fragments and chromatin pellet through the sucrose cushion.