What is a cytokine ELISPOT assay?
The cytokine enzyme-linked immunospot (ELISPOT) assay is a versatile and highly sensitive method for the ex-vivo quantification of cytokine secreting T cells after stimulation with an antigen in vitro. In fact, each cell can be detected by the assay as long as a characteristic protein is released and specific antibodies are available. The ELISPOT assay is very similar to an ELISA and is based on the same immunochemical ‘sandwich’ principle. The major difference is that an ELISPOT is a combination of both an immunoassay and bioassay because living cells are cultured directly in the wells of the ELISPOT plate. In the first step, anti-cytokine capture antibodies are immobilized onto the solid phase. Activated T cells are subsequently brought into the wells and incubated for a certain length of time. The released cytokines are trapped by the capture antibody in the immediate vicinity of the producing cells and then visualized by a combination of a second antibody coupled to an enzyme and a
