Immunofluorescence studies on formalin-fixed and paraffin-embedded material

In an attempt to apply immunomorphologic techniques to formalin-fixed material, various tissues were studied by indirect immunofluorescence. To minimize nonspecific background staining, formalin-fixed paraffin sections were treated with pronase prior to incubation with the antisera. This technique was published by Huang in 1975 to study hepatitis B core and surface antigen in formalin-fixed liver-tissue. Our examination demonstrate that this technique might enable the morphologist to identify immunoglobulins in formalin-fixed tissues and so to get new criteria for their diagnosis.