The ex vivo culture of intact fetal thymus lobes, fetal thymic organ culture (FTOC) has proven to be a useful technique for the elucidation of the molecular and cellular bases of T-cell development and T-cell receptor (TCR) repertoire selection (reviewed inref. 1. Most dramatically, FTOC has been used to determine the role of peptides in positive and negative selection, which has helped to shed light on the complex mechanism whereby the T-cell repertoire is tolerized to self (reviewed inref. 2).
