Immunological characterization of amyloid fibrils in tissue sections.

The labelling of rabbit antiserum against purified and alkaline-degraded amyloid fibrils with fluorescein isothiocyanate (FITC), has enabled the detection of amyloid deposits in various tissue sections by direct immunofluorescence. There was antigenic identity between amyloid from different organs of the same patient. In addition, indirect immunofluorescence revealed individual antigenic specificity and cross-reactivity among amyloid from different individuals. A close relationship between deposits of amyloid, immunoglobulins and complement was observed when using FITC-and rhodamine-labelled antisera against various human plasma components.