A panel of outstanding investigators surveys and explains the major cutting-edge methods used in thryroid receptor (TR) research and explains their practical experimental details. Described in step-by-step detail to ensure robust experimental results, the techniques presented cover a wide variety of key areas, including TR in development and knockout (mouse and Xenopus), transcriptional regulation by TRs in both cell–free systems and in living cells, and TR mutant analysis of patients. Additional methods provide powerful tools for the isolation of TR-regulated protein complexes, for studying the oncogene v-Erba in blood cell differentiation, and for target gene analysis in the brain. Microarray chip methods are also presented for analyzing the organs of transgenic mice to identify target genes in the liver.