Measuring Chromatin Interaction Dynamics on the Second Time Scale at Single-Copy Genes

Abstract

Capturing Binding Location and Speed Transcription factor–binding sites in chromatin can be mapped by the chromatin immunoprecipitation (ChIP) assay, which analyzes formaldehyde-fixed chromatin fragments obtained from cells. However, the standard ChIP assay does not provide information about how stable the inter-actions are. Other approaches, including live-cell imaging, can reveal aspects of the dynamic behavior of transcription factors but are limited either in location precision or time resolution. Poorey et al. (p. 369 , published online 3 October) developed a model to explain how the ChIP signal relates to formaldehyde cross-linking time, and they developed a method to measure chromatin site–specific binding dynamics with high temporal resolution.