Demonstration of AA-protein in formalin-fixed, paraffin-embedded tissues.
AA-protein was identified by SDS-acrylamide electrophoresis in amyloid fibrils fixed in formalin after isolation from fresh-frozen tissues obtained from patients with familial Mediterranean fever (FMF) amyloidosis and idiopathic AA-amyloidosis and, following deparaffination, rehydration and homogenization of embedded formalin-fixed tissues of old autopsy cases of the hereditary amyloidosis of FMF and amyloidosis acquired in association with tuberculosis, bronchiectasis, and rheumatoid arthritis. That AA-protein is unaltered by formalin was firmly established by agar gel diffusion using specific rabbit anti-AA serum. By contrast, AL proteins could not be demonstrated either in formalin-fixed amyloid fibrils derived from fresh-frozen tissues of a patient with presumably AL-amyloidosis dominated by cardiomegaly and one with AL-kappa amyloidosis or in blocks of cases of familial neuropathic amyloidosis, multiple myeloma, and idiopathic amyloidosis with cardiopathy. AA-protein is not denatured by formalin and retains its typical electrophoretic, chromatographic, and immunologic characteristics even 30 years after fixation and paraffin-embedding.
D000682:Amyloid / Q000032:analysis*; D000686:Amyloidosis / Q000378:metabolism; D001344:Autopsy; D046508:Culture Techniques; D004591:Electrophoresis, Polyacrylamide Gel; D005557:Formaldehyde / Q000494:pharmacology; D005629:Frozen Sections; D006801:Humans; D011489:Protein Denaturation; D000685:Serum Amyloid A Protein / Q000032:analysis*; D013997:Time Factors
D000682:Amyloid; D000685:Serum Amyloid A Protein; D005557:Formaldehyde