Technical Articles

Prior to the 1990s, antigen-specific T cells were primarily detected using functional assays like LDA or ELISPOT, which indirectly measured T cell frequency through proliferation or cytokine secretion. These methods lacked TCR information, could not distinguish cell states, and had limited sensitivity for rare populations (<0.01%). Furthermore, their reliance on cell viability often altered native states, failing to accurately reflect the in vivo T cell repertoire.