Monofunctional 3 to 10 nm Covalent Gold Labels for CryoEM

DESCRIPTION (provided by applicant): Gold nanoparticles are the label of choice for electron microscopy (EM) since they offer a choice of sizes that provide quantitative, high-resolution identification of targets. Recently, high-resolution EM methods including cryoEM and electron tomography have benefitted from significant advances in instrumentation and a series of breakthroughs in specimen processing and preparative equipment that have made these methods widely accessible. However, conventional colloidalgold labels do not allow the full realization of the potential in these methods, because they require extensive stabilization with large macromolecules that limit penetration and antigen access, and also because their mechanism of conjugation, through adsorption to targeting antibodies or proteins, does not allow direct labeling of specific reactive sites within macromolecular complexes at sufficiently high resolution. Nanoprobes has developed 1.4 nm (Nanogold) and 0.8 nm (Undecagold) gold nanoparticle