How many cells are secreting a specific cytokine?

Counting individual cells actively secreting a specific cytokine, rather than measuring only the pooled total.

References

• Czerkinsky, C.C., Nilsson, L.A., Nygren, H., Ouchterlony, O., Tarkowski, A. "A Solid-Phase Enzyme-Linked Immunospot (ELISPOT) Assay for Enumeration of Specific Antibody-Secreting Cells." Journal of Immunological Methods 65, nos. 1–2 (1983): 109–121.