Detection of tumor antigen-specific T cells at the site of vaccination. Subcutaneous tissue was obtained by fine needle biopsy from a vaccination site that showed signs of inflammation during the week following a boost injection at a distant site. After mechanical dissociation, cells were cultured in the presence cytokines (rhIL2 100 IU/ml and rhIL7 10 ng/ml). At day 8 the cells were stained with anti-CD8^FITC mAb and with the indicated A2/peptide multimers^PE.