The invention is a method for detecting and measuring T-cell receptor (TCR) repertoires from mammalian lymphocytes. The method is based on the use of the multiple sets of unique primers to amplify 22 regions of the TCR V.beta. region and thereby detect clonal expansions related to antigen stimulation of the immune system. Kits containing sets of primers and specialized analytical statistical software for use in determining clonal expansion in humans and mice are disclosed. The reliability, efficiency and short assay time in using the method is well suited to monitoring immune response to vaccination and therapeutic treatments for immune disorders.