Fluorometric Examination of Tissue Amyloid Fibrils in Murine Senile Amyloidosis: Use of the Fluorescent Indicator, Thioflavine T

Abstract

Thioflavine T (ThT), a fluorescent indicator of amyloid fibrils, has been tested in unfractionated tissue homogenates. With 250nM of ThT, liver homogenates from 17-month-old SAM-P/l (senescence accelerated mouse-prone), which contained amyloid fibrils in murine senile amyloidosis (fAS_SAM) fluoresced brightly, while normal liver homogenates showed a negligible fluorescence. We determined the concentration of fAS_SAM in the tissue, from the fluorescence and using the standard curve for fAS_SAM determination. Lower limits of fAS_SAM determination were about 1μg/mg tissue. A marked regional heterogeneity of fAS_SAM deposition was observed in the liver. We observed a linear correlation between fAS_SAM concentration and percentage of amyloid positive area in the liver. Age dependent increases in fAS_SAM concentrations and total fAS_SAM contents were noted in the liver and spleen of 11 to 15-month-old SAM-P/1.