DELFIA® Assay Principle
DELFIA® (dissociation-enhanced lanthanide fluorescence immunoassay) is a time-resolved fluorescence (TRF) intensity technology. Assays are designed to detect the presence of an analyte of interest using lanthanide chelate labeled reagents. Wash steps are used to eliminate unbound reagent.
DELFIA assays can be performed in either direct antigen, indirect antibody sandwich, or competitive assay formats. The technology can equally be applied to fixed or adherent cells.
How DELFIA assays work
DELFIA has a similar workflow to that of a traditional ELISA. Let’s take the example of an immuno assay setup with a direct antibody coating.
First the plate is coated with a capture antibody. After an overnight incubation, the plate is washed 3 times. The sample is then added and incubated 1.5 hours before a further 3 washing steps. The detection antibody is incubated for 1.5 hours before 3 more washing steps. At that stage, the analyte is sandwiched between the 2 antibodies. The final addition of an enhancement solution will increase the sensitivity of the assay. The lanthanide chelate is dissociated and a new highly fluorescent chelate is formed within a protective micellar solution. The fluorescence emitted can be measured with a plate reader capable of TRF detection.
Long signal stability
Broad sample compatibility
Wide detectable range