Immunofluorescence
The immunofluorescence assays are the ones that use the light from a fluorescence microscope for the detection of antigens against the influenza virus. The fluorescence microscope gives results in almost 2-4 hours with higher sensitivity and greater specificity. Both indirect fluorescent antibody (IFA) and direct fluorescent antibody (DFA) attains appearing in the assay to help detect the viral antigens for influenza A and B in the respiratory tract specimens. The fluorescent microscope is not enough for further identification and subtyping of influenza A and influenza B viruses.