Direct fluorescence method

Direct fluorescence method: Staining samples with antibodies directly labeled with fluorescein. The advantage of this method is strong specificity, but the disadvantage is that the corresponding fluorescent antibody must be prepared for each antigen detection.

Indirect fluorescence method: the primary antibody is combined with the antigen in the specimen, and then stained with fluorescein-labeled secondary antibody. The advantage of this method is that the sensitivity is higher than that of the direct method. The second antibody labeled with fluorescein can be used to detect various antigens, but the non-specific fluorescence will also increase.