A time-resolved fluorescence immunoassay (DELFIA) increases the sensitivity of antigen-driven cytokine detection.

In an effort to improve the quantification of the low levels of cytokines released in response to antigenic stimulation of T cells, a sandwich dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA) was developed and compared to a standard sandwich ELISA. The DELFIA enhanced the sensitivity of a mouse IL-2 assay 8- to 27-fold, and a human GM-CSF assay 10-fold, as compared to colorimetric ELISA. The increase in sensitivity allows for the use of lower sample volumes per well, and the ability to run more assays per supernatant sample. This sensitive, nonisotopic alternative to other cytokine detection methods will be useful for those researchers wanting to quantitate low levels of antigen-driven cytokine production.