| IFA | Indirect Fluorescent Antibody | (IFA) is the detection of antibodies to specific antigenic material in the substrate using fluorescent microscopy. Using fluorescently conjugated antibodies which are specific for a particular isotype of antibody, it is possible to distinguish IgG, IgA and IgM isotypes of specific antibodies using IFA. This sensitive technique is highly specific in well-trained hands and recent developments in the establishment of internationally recognized standard materials have led to accurate quantitation of antibody concentrations through endpoint titration (the highest serial dilution of specimen at which specific fluorescence remains) and through measuring visual intensity of fluorescence compared to known reference standard material. |