In Vitro Promoter Analysis Using Nuclear Extracts and G-Free Cassette Vectors

Nuclear extracts prepared by appropriate methods contain all of the components for transcription (1 ). Although nuclear extracts are not defined like transcription systems utilizing purified transcription components (2 –4 ) the extracts can be used to study aspects of promoter regulation. If suitable nuclear extracts can be prepared that contain the necessary transcription factors in an active state, and suitable DNA templates containing regulator sequences are available, processes such as differential gene expression (5 ,6 ) and hormonal simulation of transcription can be reconstituted (7 ,8 ).