Reproducibility and Repeatability of Assessment of Myocardial Light Chain Amyloidosis Burden Using F-Florbetapir PET/CT.

Background: F-florbetapir PET is emerging as an excellent quantitative tool to quantify cardiac light chain (AL) amyloidosis burden. The primary aim of this study was to determine interobserver reproducibility and intraobserver repeatability, defined per the recommendations of the Quantitative Imaging Biomarker Alliance technical performance group, of PET F-florbetapir retention index (RI) in patients with cardiac AL amyloidosis.

Methods: The study cohort comprised 37 subjects with systemic AL amyloidosis enrolled in the prospective study: Molecular Imaging of Primary Amyloid Cardiomyopathy (clinical trials.

Quintuple labeling in the electron microscope with genetically encoded enhanced horseradish peroxidase.

Genetic encoded multilabeling is essential for modern cell biology. In fluorescence microscopy this need has been satisfied by the development of numerous color-variants of the green fluorescent protein. In electron microscopy, however, true genetic encoded multilabeling is currently not possible.