Elispot is a workhorse for functional analysis of single immune cells. Originally established for the enumeration of specific antibody-secreting B cells in 1983 [1], the technology has been expanded to the analysis of T cells, NK cells and monocytes. The assay is typically carried out in 96 well plates with a nitrocellulose or PVDF membrane, which is coated with an antibody that is directed against the analyte of interest. Cells and stimulants are added to the plate, and secreted analyte is captured in the immediate surroundings of the cell. After cell removal, bound analyte is made visible via the addition of a biotinylated secondary antibody, avidin-enzyme complex and substrate that precipitates onto the membrane and forms spots which can be automatically enumerated. Each spot represents one cell that secreted the analyte. The most common analytes investigated today are cytokines (IFNɣ, IL-2, IL-5, IL-10, IL-17, Granzyme B, TNF, GM-CSF and many more) and immunoglobulins. Others can also be evaluated, such as chemokines (e.g., CXCL8) or apolipoproteins.Author: Sylvia JanetzkiPublished as a short report in the Journal for ImmunoTherapy of Cancer (2015) 3:30.#SITCPublication