T cell hybridomas can be obtained by fusing activated T cells with tumor cells. A heterogeneous population of hybridomas can be cloned by limiting dilution to obtain hybridomas that express specificity to one T cell receptor (TCR). This unit describes cell fusion and selection of T cell hybridomas. A protocol is provided for screening of T cell hybridomas for expression of the CD3-TCR complex by flow cytometry analysis. Those hybridomas expressing a CD3-TCR complex are then further tested for expression of antigen specificity by screening for specific antigen-induced lymphokine production. The procedures for establishment of stable hybridoma lines and cloning of stable lines by limiting dilution are identical to those described for B cell hybridomas and can be found in UNIT 2.5. Protocols for freezing and thawing T cell hybridomas are identical to those described for B cell hybridomas and other cell lines.