TIME-RESOLVED IMMUNOFLUOROMETRIC ASSAY FOR HUMAN INTERFERON-GAMMA

A time-resolved immunofluorometric assay (TR-IFMA) for interferon-gamm a (IFN-gamma) was developed and its properties were compared with thos e of previously reported immunoenzymometric assays (IEMAs). The advant age of TR-IFMA is not only that it is as sensitive as the usual colori metric IEMA, but that it is also feasible and fast as a detection proc edure of europium. It was modified in order to make it more sensitive and faster by changing the antiserum and incubation conditions. The im proved assay could directly measure IFN-gamma in human plasma without any pretreatment. The detection limit for IFN-gamma is 40 pg/ml, and a n assay can be completed within 6 h.