Immunofluorescent slides of liver allografts may be difficult to interpret at times. Usually, there is alot of background staining for IgG in the portal tract connective tissue and fibrinogen is frequently detected in the sinusoids, even in the absence of humoral rejection. In addition, the lipofuschin pigment shows yellow autofluorescence, in contrast to the green color of fluorescein, which labels the antibodies. |