DETECTION OF SERUM AMYLOID A-DERIVED PROTEINS IN FORMALIN-FIXED PARAFFIN-EMBEDDED TISSUES - RELIABILITY OF THE METHOD AND EXPANSION OF ITS SPECTRUM

To further assess the reliability of the Shtrasburg method for detecti on of amyloid A in formalin-fixed, paraffin-embedded tissues and to ex pand the spectrum of the amyloid proteins analyzed by this method, we studied formalin-fixed, paraffin-embedded amyloid-containing tissues o btained from patients with the following types of amyloidosis: amyloid A, light chain, transthyretin, calcitonin, beta 2 microglobulin, and senile seminal vesicle. The tissue samples were deparaffinized, proces sed, and subjected to sodium dodecyl sulfate-polyacrylamide gel electr ophoresis and the Western blot technique. Only specimens from patients with amyloid A amyloidosis gave protein bands: a single 8.5-kd band i n lanes of all tissues studied, except thyroid tissue, which displayed two bands of about 5 and 10 kd. Other types of amyloid failed to show any protein band. These findings suggest that the Shtrasburg method i s sensitive, specific, and reliable and may have an important role in the diagnosis of amyloidosis.