Preparation of nuclear extracts is the first step in examining transcription factor activity. Cayman’s Nuclear Extraction is formulated for the quick and simple isolation of nuclear and cytoplasmic fractions from cultured cells and tissue homogenates that can be used successfully in Cayman’s Transcription Factor Assay kits. The proteins isolated using this kit can also be used in electrophoretic mobility shift assays (EMSA) and western blotting applications.