EUROIMMUN: Indirect immunofluorescence: an easy and modern method

Indirect immunofluorescence: an easy and modern method Principle of the test For the determination of autoantibodies or antibodies against infectious agents, cells, tissue sections or purified, biochemically characterized substances are used as antigen substrates. If the sample is positive, specific antibodies in the diluted serum sample attach to the antigens coupled to a solid phase. In a second step, the attached antibodies are stained with fluorescein-labelled anti-human antibodies and visualized with the fluorescence microscope. Positive samples can be titrated in steps. The most suitable titration interval is provided by the dilution factor 3.162 (square root of 10). In this way, every second step represents in its denominator an integral power of 10 (1:10, 1:32, 1:100, 1 : 320, 1 : 1000, 1 : 3200, 1 : 10000 etc.).