This kit is ideal for users who want a convenient and sensitive assay. The assay is designed for the enumeration of cells secreting human Interleukin-3 (IL-3). The kit includes ELISpot plates pre-coated with monoclonal antibody, biotinylated detection antibody, Streptavidin-ALP and ready-to-use BCIP/NBT-plus substrate. A polyclonal activator for human T cells (mAb CD3-2) is supplied as a positive control for cytokine secretion.